Filipinos v. State, 2003-2008

Lawsuits have gestation periods. Both of these cases inevitably begin with a boy-meet-girl encounter that leads to the birth of a child. The case then develops through several stages, one of which involves an attempt by a parent to file a status action notification that is rejected by a local registrar or other competent official. The parent then consults an attorney and files a lawsuit on behalf of the child, claiming that the rejection itself was unjust, or that the laws cited as ground for the rejection are unconstitutional.

第一審裁判所名：東京地方裁判所

第一審事件番号：平成15(行ウ)110

第一審裁判年月日：平成17年04月13日

第一審判決：

Court of first instance: Tokyo District Court

First instance case number: Heisei 15 [2003] (Gyo-U) 110

Date of first instance decision: 13 April 2005 [Heisei 17-04-13]

Ruling:

原審裁判所名：東京高等裁判所

原審事件番号：平成17(行コ)134

原審裁判年月日：平成18年02月28日

原審判決：

Court of original instance: Tokyo High Court

Original instance case number: Heisei 17 [2005] (Gyo-Ko) 134

Date of original instance decision: 28 February 2006 [Heisei 19-02-27]

Original instance ruling:

事件番号：平成18(行ツ)135

事件名：退去強制令書発付処分取消等請求事件





裁判年月日：平成20年06月04日

法廷名：最高裁判所大法廷

裁判種別：判決

結果：破棄自判

判例集巻・号・頁：第62巻6号1367頁

Case number: Heisei 18 [2006] (Gyo-Tsu) 135

Case name: Case to seek revocation of the disposition of issuance of a written deportation order

Case name: Case seeking nullification of [ministerial] action [disposition against plaintiff] of issuance of a [written] deportation order [notice of order of compulsory leave)] et cetera

Date of judgment: 4 June 2008 [Heisei 20-06-04]

Court name: Supreme Court, Grand Bench

Type of judgment: Ruling

Results: Quashed original ruling and issued own judgment [Article 3 unconstitutional, boy is Japanese]

Hanreishū [Court Reports] Volume, Number, Page:
Volume 62, Number 6, Page 1367

１　国籍法３条１項が，日本国民である父と日本国民でない母との間に出生した後に父から認知された子につき，父母の婚姻により嫡出子たる身分を取得した(準正のあった）場合に限り日本国籍の取得を認めていることによって国籍の取得に関する区別を生じさせていることと憲法１４条１項

２日本国民である父と日本国民でない母との間に出生した後に父から認知された子は，日本国籍の取得に関して憲法１４条１項に違反する区別を生じさせている，父母の婚姻により嫡出子たる身分を取得したという部分（準正要件）を除いた国籍法３条１項所定の国籍取得の要件が満たされるときは，日本国籍を取得するか

Judgment concerning the relationship between a distinction in granting Japanese nationality caused by Article 3, para. 1 of the Nationality Act which provides that a child born out of wedlock to a Japanese father and a non-Japanese mother and acknowledged by the father after birth may acquire Japanese nationality only if the child has acquired the status of a child born in wedlock as a result of the marriage of the parents, and Article 14, para. 1 of the Constitution.

１　国籍法３条１項が，日本国民である父と日本国民でない母との間に出生した後に父から認知された子について，父母の婚姻により嫡出子たる身分を取得した（準正のあった）場合に限り届出による日本国籍の取得を認めていることによって，認知されたにとどまる子と準正のあった子との間に日本国籍の取得に関する区別を生じさせていることは，遅くとも上告人が国籍取得届を提出した平成１５年当時において，憲法１４条１項に違反していたものである。

２　日本国民である父と日本国民でない母との間に出生した後に父から認知された子は，国籍法３条１項所定の国籍取得の要件のうち，日本国籍の取得に関して憲法１４条１項に違反する区別を生じさせている部分，すなわち父母の婚姻により嫡出子たる身分を取得したという部分（準正要件）を除いた要件が満たされるときは，国籍法３条１項に基づいて日本国籍を取得する。

(１，２につき補足意見，意見及び反対意見がある。）

1. Article 3, para. 1 of the Nationality Act provides that a child born out of wedlock to a Japanese father and a non-Japanese mother and acknowledged by the father after birth may acquire Japanese nationality only if the child has acquired the status of a child born in wedlock as a result of the marriage of the parents, thereby causing a distinction in granting Japanese nationality, and in 2003, at the latest, this distinction was in violation of Article 14, para. 1 of the Constitution.

2. A child born out of wedlock to a Japanese father and a non-Japanese mother and acknowledged by the father after birth shall acquire Japanese nationality if the child satisfies the requirements for acquisition of Japanese nationality prescribed in Article 3, para. 1 of the Nationality Act, except for the requirement of acquiring the status of a child born in wedlock as a result of the marriage of the parents.

(There are concurring opinions and dissenting opinions.)

（１，２につき）憲法10条，憲法14条1項，国籍法3条1項　（１につき）国籍法2条1号　（２につき）憲法81条

(Concerning 1 and 2)Article 10 and Article 14, para. 1 of the Constitution, Article 3, para. 1 of the Nationality Act,(Concerning 1)Article 2, item 1 of the Nationality Act,(Concerning 2) Article 81 of the Constitution

Article 14, para. 1 of the Constitution

All of the people are equal under the law and there shall be no discrimination in political, economic or social relations because of race, creed, sex, social status or family origin.

Article 3, para. 1 of the Nationality Act

(Acquisition of Japanese Nationality by Legitimation)

A child who has acquired the status of a child born in wedlock as a result of the marriage of the parents and the acknowledgment by either parent and who is aged under 20 (excluding those who have been Japanese citizens) may acquire Japanese nationality by making a notification to the Minister of Justice, if the father or mother who has acknowledged the child was a Japanese citizen at the time of the child's birth, and such father or mother is currently a Japanese citizen or was a Japanese citizen at the time of his/her death.

Article 2, item 1 of the Nationality Act

(Acquisition of Japanese Nationality by Birth)

A child shall be a Japanese citizen in the following cases:

(i) Where the father or mother is a Japanese citizen at the time of birth.

Article 81 of the Constitution

The Supreme Court is the court of last resort with power to determine the constitutionality of any law, order, regulation or official act.

原判決を破棄する。

被上告人の控訴を棄却する。

控訴費用及び上告費用は被上告人の負担とする。

The judgment of prior instance is quashed.

The appeal to the court of second instance filed by the appellee of final appeal is dismissed.

The appellee of final appeal shall bear the cost of the appeal to the court of second instance and the cost of the final appeal.

上告代理人山口元一の上告理由第１ないし第３について

１ 事案の概要

本件は，法律上の婚姻関係にない日本国民である父とフィリピン共和国籍を有する母との間に本邦において出生した上告人が，出生後父から認知されたことを理由として平成１５年に法務大臣あてに国籍取得届を提出したところ，国籍取得の条件を備えておらず，日本国籍を取得していないものとされたことから，被上告人に対し，日本国籍を有することの確認を求めている事案である。

Concerning Reasons I to III for final appeal argued by the appeal counsel, YAMAGUCHI Genichi

1. Outline of the case

The appellant of final appeal, who was born to a father who is a Japanese citizen and a mother who has nationality of the Republic of the Philippines, a couple having no legal marital relationship, submitted a notification for acquisition of Japanese nationality to the Ministry of Justice in 2003 on the grounds that he/she was acknowledged by the father after birth, but the minister determined that the appellant had not acquired Japanese nationality due to the failure to meet the requirements for acquisition of Japanese nationality. In this case, the appellant sued the appellee, seeking a declaration that the appellant has Japanese nationality.

２ 国籍法２条１号，３条について

国籍法２条１号は，子は出生の時に父又は母が日本国民であるときに日本国民とする旨を規定して，日本国籍の生来的取得について，いわゆる父母両系血統主義によることを定めている。したがって，子が出生の時に日本国民である父又は母との間に法律上の親子関係を有するときは，生来的に日本国籍を取得することになる。

国籍法３条１項は，u父母の婚姻及びその認知により嫡出子たる身分を取得した子で２０歳未満のもﾌ（日本国民であっｽ者を除く。）は，認知をした父又は母が子の出生の時に日本国民であった場合にｨいて，そﾌ父又は母が現に日本国民であるとき，又はその死亡の時に日本国民であったときはC法務大臣ﾉ届け出ることによって，日本の国籍を取得することができる。」と規定し，同条２項は，「前項の [P2] 規定による届出をした者は，その届出の時に日本の国籍を取得する。」と規定してい驕B同条１項は，父又は母が認知をした場合について規定しているが，日本国民である母の非嫡出子は，出生により母との間に法律上の親子ﾖ係が生ずると解され，また，日本国民である父が胎児認知した子は，出生時に父との間に法律上の親子関係が生ずることとなり，それぞれ同法２条１号により生来的に日本国籍を取得することから，同法３条１項は，実際上は，法律上の婚姻関係にない日本国民である父と日本国民でない母との間に出生した子で，父から胎児認知を受けていないものに限り適用されることになる。

2. Concerning Article 2, item 1 and Article 3 of the Nationality Act

Article 2, item 1 of the Nationality Act provides that a child shall be a Japanese citizen if the father or mother is a Japanese citizen at the time of birth, applying the principle of jus sanguinis (the principle of granting nationality to a child based on the child's blood relationship with the father or mother) when determining the acquisition of Japanese nationality by birth. Therefore, if a child has a legal parent-child relationship with a Japanese father or Japanese mother at the time of birth, the child shall acquire Japanese nationality by birth.

Article 3, para. 1 of the Nationality Act provides that "A child who has acquired the status of a child born in wedlock as a result of the marriage of the parents and the acknowledgment by either parent and who is aged under 20 (excluding those who have been Japanese citizens) may acquire Japanese nationality by making a notification to the Minister of Justice, if the father or mother who has acknowledged the child was a Japanese citizen at the time of the child's birth, and such father or mother is currently a Japanese citizen or was a Japanese citizen at the time of his/her death." Para.2 of said Article provides that "A person who has made a notification under the provision of the preceding paragraph shall acquire Japanese nationality at the time of notification." Article 3, para. 1 of said Act addresses cases where either the father or mother has acknowledged the child. However, it is construed that a child born out of wedlock to a Japanese mother is to have a legal parent-child relationship with the mother by birth, and a child acknowledged by a Japanese father before birth is to have a legal parent-child relationship with the father upon birth, and in both cases, the child shall acquire Japanese nationality by birth under Article 2, item 1 of said Act. Consequently, Article 3, para. 1 of said Act is practically applied only to a child who was born to a couple of a Japanese father and a non-Japanese mother having no legal marital relationship and who was not acknowledged by the father before birth.

３ 原判決等

上告人は，国籍法２条１号に基づく日本国籍の取得を主張するほか，日本国民である父の非嫡出子について，父母の婚姻により嫡出子たる身分を取得した者のみが法務大臣に届け出ることにより日本国籍を取得することができるとした同法３条１項の規定が憲法１４条１項に違反するとして，上告人が法務大臣あてに国籍取得届を提出したことにより日本国籍を取得した旨を主張した。

これに対し，原判決は，国籍法２条１号に基づく日本国籍の取得を否定した上，同法３条１項に関する上記主張につき，仮に同項の規定が憲法１４条１項に違反し，無効であったとしても，そのことから，出生後に日本国民である父から認知を受けたにとどまる子が日本国籍を取得する制度が創設されるわけではなく，上告人が当然に日本国籍を取得することにはならないし，また，国籍法については，法律上の文言を厳密に解釈することが要請され，立法者の意思に反するような類推解釈ないし拡張解釈は許されず，そのような解釈の名の下に同法に定めのない国籍取得の要件を創設することは，裁判所が立法作用を行うものとして許されないから，上 [P3] 告人が同法３条１項の類推解釈ないし拡張解釈によって日本国籍を取得したということもできないと判断して，上告人の請求を棄却した。

3. Judgment of prior instance, etc.

The appellant alleged his/her acquisition of Japanese nationality under Article 2, item 1 of the Nationality Act, and also alleged that he/she had acquired Japanese nationality by submitting a notification for acquisition of Japanese nationality to the Minister of Justice, on the grounds that Article 3, para. 1 of said Act, which provides that in the case of a child born out of wedlock to a Japanese father, only such child who has acquired the status of a child born in wedlock as a result of the marriage of the parents may acquire Japanese nationality by making a notification to the Minister of Justice, is in violation of Article 14, para. 1 of the Constitution.

While denying the appellant's acquisition of Japanese nationality under Article 2, para. 1 of the Nationality Act, the judgment of prior instance held as follows with regard to the allegation concerning Article 3, para. 1 of said Act. Even supposing that the provision of said paragraph should be in violation of Article 14, para. 1 of the Constitution and therefore void, this does not lead to creating a new system for granting Japanese nationality to a child born out of wedlock who only satisfied the requirement of acknowledgment by a Japanese father after birth (but does not satisfy the requirement of the marriage of the parents), nor does it cause the appellant to automatically acquire Japanese nationality. Furthermore, since the Nationality Act must be subject to strict literal construction, the court is never permitted to put an analogical or broad construction on the provisions of said Act contrary to the lawmakers' intention, and if the court, under the name of such legal construction, creates any requirement for acquisition of Japanese nationality that is not stipulated in the Act, this is equal to the case where the court performs a legislative act and therefore unacceptable. Therefore, the appellant cannot be deemed to have acquired Japanese nationality according to an analogical or broad construction of the provision of Article 3, para. 1 of said Act. In conclusion, the judgment of prior instance dismissed the appellant's claim.

４ 国籍法３条１項による国籍取得の区別の憲法適合性について

所論は，上記のとおり，国籍法３条１項の規定が憲法１４条１項に違反する旨をいうが，その趣旨は，国籍法３条１項の規定が，日本国民である父の非嫡出子について，父母の婚姻により嫡出子たる身分を取得した者に限り日本国籍の取得を認めていることによって，同じく日本国民である父から認知された子でありながら父母が法律上の婚姻をしていない非嫡出子は，その余の同項所定の要件を満たしても日本国籍を取得することができないという区別（以下「本件区別」という。）が生じており，このことが憲法１４条１項に違反する旨をいうものと解される。所論は，その上で，国籍法３条１項の規定のうち本件区別を生じさせた部分のみが違憲無効であるとし，上告人には同項のその余の規定に基づいて日本国籍の取得が認められるべきであるというものである。そこで，以下，これらの点について検討を加えることとする。

(1) 憲法１４条１項は，法の下の平等を定めており，この規定は，事柄の性質に即応した合理的な根拠に基づくものでない限り，法的な差別的取扱いを禁止する趣旨であると解すべきことは，当裁判所の判例とするところである（最高裁昭和３７年（オ）第１４７２号同３９年５月２７日大法廷判決・民集１８巻４号６７６頁，最高裁昭和４５年（あ）第１３１０号同４８年４月４日大法廷判決・刑集２７巻３号２６５頁等）。

憲法１０条は，「日本国民たる要件は，法律でこれを定める。」と規定し，これを受けて，国籍法は，日本国籍の得喪に関する要件を規定している。憲法１０条の [P4] 規定は，国籍は国家の構成員としての資格であり，国籍の得喪に関する要件を定めるに当たってはそれぞれの国の歴史的事情，伝統，政治的，社会的及び経済的環境等，種々の要因を考慮する必要があることから，これをどのように定めるかについて，立法府の裁量判断にゆだねる趣旨のものであると解される。しかしながら，このようにして定められた日本国籍の取得に関する法律の要件によって生じた区別が，合理的理由のない差別的取扱いとなるときは，憲法１４条１項違反の問題を生ずることはいうまでもない。すなわち，立法府に与えられた上記のような裁量権を考慮しても，なおそのような区別をすることの立法目的に合理的な根拠が認められない場合，又はその具体的な区別と上記の立法目的との間に合理的関連性が認められない場合には，当該区別は，合理的な理由のない差別として，同項に違反するものと解されることになる。

日本国籍は，我が国の構成員としての資格であるとともに，我が国において基本的人権の保障，公的資格の付与，公的給付等を受ける上で意味を持つ重要な法的地位でもある。一方，父母の婚姻により嫡出子たる身分を取得するか否かということは，子にとっては自らの意思や努力によっては変えることのできない父母の身分行為に係る事柄である。したがって，このような事柄をもって日本国籍取得の要件に関して区別を生じさせることに合理的な理由があるか否かについては，慎重に検討することが必要である。

(2)ア国籍法３条の規定する届出による国籍取得の制度は，法律上の婚姻関係にない日本国民である父と日本国民でない母との間に出生した子について，父母の婚姻及びその認知により嫡出子たる身分を取得すること（以下「準正」という。）のほか同条１項の定める一定の要件を満たした場合に限り，法務大臣への届出によ [P5] って日本国籍の取得を認めるものであり，日本国民である父と日本国民でない母との間に出生した嫡出子が生来的に日本国籍を取得することとの均衡を図ることによって，同法の基本的な原則である血統主義を補完するものとして，昭和５９年法律第４５号による国籍法の改正において新たに設けられたものである。

そして，国籍法３条１項は，日本国民である父が日本国民でない母との間の子を出生後に認知しただけでは日本国籍の取得を認めず，準正のあった場合に限り日本国籍を取得させることとしており，これによって本件区別が生じている。このような規定が設けられた主な理由は，日本国民である父が出生後に認知した子については，父母の婚姻により嫡出子たる身分を取得することによって，日本国民である父との生活の一体化が生じ，家族生活を通じた我が国社会との密接な結び付きが生ずることから，日本国籍の取得を認めることが相当であるという点にあるものと解される。また，上記国籍法改正の当時には，父母両系血統主義を採用する国には，自国民である父の子について認知だけでなく準正のあった場合に限り自国籍の取得を認める国が多かったことも，本件区別が合理的なものとして設けられた理由であると解される。

イ日本国民を血統上の親として出生した子であっても，日本国籍を生来的に取得しなかった場合には，その後の生活を通じて国籍国である外国との密接な結び付きを生じさせている可能性があるから，国籍法３条１項は，同法の基本的な原則である血統主義を基調としつつ，日本国民との法律上の親子関係の存在に加え我が国との密接な結び付きの指標となる一定の要件を設けて，これらを満たす場合に限り出生後における日本国籍の取得を認めることとしたものと解される。このような目的を達成するため準正その他の要件が設けられ，これにより本件区別が生じたので [P6] あるが，本件区別を生じさせた上記の立法目的自体には，合理的な根拠があるというべきである。

また，国籍法３条１項の規定が設けられた当時の社会通念や社会的状況の下においては，日本国民である父と日本国民でない母との間の子について，父母が法律上の婚姻をしたことをもって日本国民である父との家族生活を通じた我が国との密接な結び付きの存在を示すものとみることには相応の理由があったものとみられ，当時の諸外国における前記のような国籍法制の傾向にかんがみても，同項の規定が認知に加えて準正を日本国籍取得の要件としたことには，上記の立法目的との間に一定の合理的関連性があったものということができる。

ウしかしながら，その後，我が国における社会的，経済的環境等の変化に伴って，夫婦共同生活の在り方を含む家族生活や親子関係に関する意識も一様ではなくなってきており，今日では，出生数に占める非嫡出子の割合が増加するなど，家族生活や親子関係の実態も変化し多様化してきている。このような社会通念及び社会的状況の変化に加えて，近年，我が国の国際化の進展に伴い国際的交流が増大することにより，日本国民である父と日本国民でない母との間に出生する子が増加しているところ，両親の一方のみが日本国民である場合には，同居の有無など家族生活の実態においても，法律上の婚姻やそれを背景とした親子関係の在り方についての認識においても，両親が日本国民である場合と比べてより複雑多様な面があり，その子と我が国との結び付きの強弱を両親が法律上の婚姻をしているか否かをもって直ちに測ることはできない。これらのことを考慮すれば，日本国民である父が日本国民でない母と法律上の婚姻をしたことをもって，初めて子に日本国籍を与えるに足りるだけの我が国との密接な結び付きが認められるものとすることは，今日では [P7] 必ずしも家族生活等の実態に適合するものということはできない。

また，諸外国においては，非嫡出子に対する法的な差別的取扱いを解消する方向にあることがうかがわれ，我が国が批准した市民的及び政治的権利に関する国際規約及び児童の権利に関する条約にも，児童が出生によっていかなる差別も受けないとする趣旨の規定が存する。さらに，国籍法３条１項の規定が設けられた後，自国民である父の非嫡出子について準正を国籍取得の要件としていた多くの国において，今日までに，認知等により自国民との父子関係の成立が認められた場合にはそれだけで自国籍の取得を認める旨の法改正が行われている。

以上のような我が国を取り巻く国内的，国際的な社会的環境等の変化に照らしてみると，準正を出生後における届出による日本国籍取得の要件としておくことについて，前記の立法目的との間に合理的関連性を見いだすことがもはや難しくなっているというべきである。

エ一方，国籍法は，前記のとおり，父母両系血統主義を採用し，日本国民である父又は母との法律上の親子関係があることをもって我が国との密接な結び付きがあるものとして日本国籍を付与するという立場に立って，出生の時に父又は母のいずれかが日本国民であるときには子が日本国籍を取得するものとしている（２条１号）。その結果，日本国民である父又は母の嫡出子として出生した子はもとより，日本国民である父から胎児認知された非嫡出子及び日本国民である母の非嫡出子も，生来的に日本国籍を取得することとなるところ，同じく日本国民を血統上の親として出生し，法律上の親子関係を生じた子であるにもかかわらず，日本国民である父から出生後に認知された子のうち準正により嫡出子たる身分を取得しないものに限っては，生来的に日本国籍を取得しないのみならず，同法３条１項所定の届出 [P8] により日本国籍を取得することもできないことになる。このような区別の結果，日本国民である父から出生後に認知されたにとどまる非嫡出子のみが，日本国籍の取得について著しい差別的取扱いを受けているものといわざるを得ない。

日本国籍の取得が，前記のとおり，我が国において基本的人権の保障等を受ける上で重大な意味を持つものであることにかんがみれば，以上のような差別的取扱いによって子の被る不利益は看過し難いものというべきであり，このような差別的取扱いについては，前記の立法目的との間に合理的関連性を見いだし難いといわざるを得ない。とりわけ，日本国民である父から胎児認知された子と出生後に認知された子との間においては，日本国民である父との家族生活を通じた我が国社会との結び付きの程度に一般的な差異が存するとは考え難く，日本国籍の取得に関して上記の区別を設けることの合理性を我が国社会との結び付きの程度という観点から説明することは困難である。また，父母両系血統主義を採用する国籍法の下で，日本国民である母の非嫡出子が出生により日本国籍を取得するにもかかわらず，日本国民である父から出生後に認知されたにとどまる非嫡出子が届出による日本国籍の取得すら認められないことには，両性の平等という観点からみてその基本的立場に沿わないところがあるというべきである。

オ上記ウ，エで説示した事情を併せ考慮するならば，国籍法が，同じく日本国民との間に法律上の親子関係を生じた子であるにもかかわらず，上記のような非嫡出子についてのみ，父母の婚姻という，子にはどうすることもできない父母の身分行為が行われない限り，生来的にも届出によっても日本国籍の取得を認めないとしている点は，今日においては，立法府に与えられた裁量権を考慮しても，我が国との密接な結び付きを有する者に限り日本国籍を付与するという立法目的との合理的 [P9] 関連性の認められる範囲を著しく超える手段を採用しているものというほかなく，その結果，不合理な差別を生じさせているものといわざるを得ない。

カ確かに，日本国民である父と日本国民でない母との間に出生し，父から出生後に認知された子についても，国籍法８条１号所定の簡易帰化により日本国籍を取得するみちが開かれている。しかしながら，帰化は法務大臣の裁量行為であり，同号所定の条件を満たす者であっても当然に日本国籍を取得するわけではないから，これを届出による日本国籍の取得に代わるものとみることにより，本件区別が前記立法目的との間の合理的関連性を欠くものでないということはできない。

なお，日本国民である父の認知によって準正を待たずに日本国籍の取得を認めた場合に，国籍取得のための仮装認知がされるおそれがあるから，このような仮装行為による国籍取得を防止する必要があるということも，本件区別が設けられた理由の一つであると解される。しかし，そのようなおそれがあるとしても，父母の婚姻により子が嫡出子たる身分を取得することを日本国籍取得の要件とすることが，仮装行為による国籍取得の防止の要請との間において必ずしも合理的関連性を有するものとはいい難く，上記オの結論を覆す理由とすることは困難である。

(3) 以上によれば，本件区別については，これを生じさせた立法目的自体に合理的な根拠は認められるものの，立法目的との間における合理的関連性は，我が国の内外における社会的環境の変化等によって失われており，今日において，国籍法３条１項の規定は，日本国籍の取得につき合理性を欠いた過剰な要件を課するものとなっているというべきである。しかも，本件区別については，前記(2)エで説示した他の区別も存在しており，日本国民である父から出生後に認知されたにとどまる非嫡出子に対して，日本国籍の取得において著しく不利益な差別的取扱いを生じ [P10] させているといわざるを得ず，国籍取得の要件を定めるに当たって立法府に与えられた裁量権を考慮しても，この結果について，上記の立法目的との間において合理的関連性があるものということはもはやできない。

そうすると，本件区別は，遅くとも上告人が法務大臣あてに国籍取得届を提出した当時には，立法府に与えられた裁量権を考慮してもなおその立法目的との間において合理的関連性を欠くものとなっていたと解される。

したがって，上記時点において，本件区別は合理的な理由のない差別となっていたといわざるを得ず，国籍法３条１項の規定が本件区別を生じさせていることは，憲法１４条１項に違反するものであったというべきである。

4. Conformity to the Constitution of the distinction in granting Japanese nationality under Article 3, para. 1 of the Nationality Act

The appeal counsel can be construed to be alleging as follows. Article 3, para. 1 of the Nationality Act provides that a child born out of wedlock to a Japanese father may acquire Japanese nationality only if the child has acquired the status of a child born in wedlock as a result of the marriage of the parents, and this provision causes a distinction between a child who satisfies this requirement and a child born out of wedlock who is also acknowledged by a Japanese father but whose parents have no legal marital relationship, in that the latter child may not acquire Japanese nationality even where he/she has satisfied other requirements prescribed in said paragraph (hereinafter referred to as the "Distinction"), and the existence of the Distinction is in violation of Article 14, para. 1 of the Constitution. The appeal counsel further alleges that the provision of Article 3, para. 1 of the Nationality Act is unconstitutional and therefore void only with respect to the part that causes the Distinction, and the appellant should be granted Japanese nationality under the remaining part of the provision of said paragraph. We therefore make examination on these points.

(1) Article 14, para. 1 of the Constitution provides for equality before the law, and as this court determined in the past cases, this provision should be construed to mean that discriminatory treatment by law should be prohibited unless it has a reasonable basis that is in line with the nature of the matters concerned (See 1962 (O) No. 1472, judgment of the Grand Bench of the Supreme Court of May 27, 1964, Minshu Vol. 18, No. 4, at 676, 1970 (A) No. 1310, judgment of the Grand Bench of the Supreme Court of April 4, 1973, Keishu Vol. 27, No. 3, at 265, etc.)

Article 10 of the Constitution provides that "The conditions necessary for being a Japanese national shall be determined by law." In accordance with this provision, the Nationality Act provides for the requirements for acquisition and loss of Japanese nationality. The provision of Article 10 of the Constitution can be construed to mean that since nationality is the qualification for being a member of a particular state, and when specifying the requirements for acquisition or loss of nationality, it is necessary to take into consideration various factors concerning each state, including historical backgrounds, tradition, and political, social and economic circumstances, the determination on the content of these requirements should be left to the discretion of the legislative body. However, if any distinction caused by the requirements under a law concerning acquisition of Japanese nationality that are specified based on such legislative discretion amounts to discriminatory treatment without reasonable grounds, such a situation, needless to say, raises a question of violation of Article 14, para. 1 of the Constitution. In other words, where a reasonable basis cannot be found in the legislative purpose of making such a distinction even if the discretionary power vested in the legislative body is taken into consideration, or where a reasonable relevance cannot be found between the distinction in question and the aforementioned legislative purpose, the distinction is deemed to constitute discrimination without reasonable grounds and to violate the provision of Article 14, para. 1 of the Constitution.

Japanese nationality is the qualification for being a member of the State of Japan, and it is also an important legal status that means a lot to people in order to enjoy the guarantee of fundamental human rights, obtain public positions or receive public benefits in Japan. On the other hand, whether or not a child can acquire the status of a child born in wedlock as a result of the marriage of the parents is a matter that depends on an act relating to the personal status of the parents, which cannot be affected by the child's own intention or efforts. Therefore, it is necessary to deliberately consider whether or not there are any reasonable grounds for causing a distinction in terms of the requirements for acquisition of Japanese nationality based on such matter.

(2)(a) Under the system for acquisition of Japanese nationality based on notification prescribed in Article 3 of the Nationality Act, a child born to a couple of a Japanese father and a non-Japanese mother having no legal marital relationship may acquire Japanese nationality by making a notification to the Minister of Justice if the child satisfies the requirements prescribed in para. 1 of said Article, including acquisition of the status of a child born in wedlock as a result of the marriage of the parents and the acknowledgement by either parent (hereinafter referred to as "legitimation"). This system was introduced upon the revision to the Nationality Act by Act No. 45 of 1984 for the purpose of supplementing the basic principle of said Act, jus sanguinis, by achieving a balance (in treatment) with a child born in wedlock to a Japanese father and a non-Japanese mother who may acquire Japanese nationality by birth.

Article 3, para. 1 of the Nationality Act does not allow a child born out of wedlock to a Japanese father and a non-Japanese mother to acquire Japanese nationality just by satisfying the requirement of being acknowledged by the father after birth, but it allows acquisition of Japanese nationality only when legitimation has taken place. This limitation is the cause of the Distinction. The primary reason that this provision was included in the Act can be construed as that in the case of a child acknowledged by a Japanese father after birth, when the child has acquired the status of a child born in wedlock as a result of the marriage of the parents, the child's life is united with the life of the Japanese father and the child obtains a close tie with Japanese society through his/her family life, and therefore it is appropriate to grant Japanese nationality to such a child. Furthermore, at the time when the revision was made to the Nationality Act, many states that adopted the principle of jus sanguinis made both acknowledgment and legitimation as requirements for granting nationality to children born to fathers who are their citizens. This may be another reason that the Distinction was introduced as a reasonable one.

(b) Even where a child is born to a Japanese citizen as his/her parent by blood, if the child does not acquire Japanese nationality by birth, he/she is likely to subsequently develop a close tie with a foreign state which is his/her state of nationality. It is construed that Article 3, para. 1 of the Nationality Act, while keeping the basic principle of the Act, the principle of jus sanguinis, provides for certain requirements that can be the indexes by which to measure the closeness of the tie between the child and Japan, in addition to the existence of a legal parent-child relationship with a Japanese citizen. In order to achieve this purpose, requirements such as legitimation were introduced and this caused the Distinction. We should say that the aforementioned legislative purpose itself, which is the cause of the Distinction, has a reasonable basis.

Furthermore, according to the socially accepted views and under the social circumstances at the time when the provision of Article 3, para. 1 of the Nationality Act was established, there may have been adequate reasons to consider that in the case of a child born to a Japanese father and a non-Japanese mother, the fact of the legal marriage of the parents would show the existence of the child's close tie with Japan developed through his/her family life with the Japanese father. In light of the aforementioned trends in the nationality law systems enforced in foreign states at the time of introduction of the provision of said paragraph, a certain reasonable relevance can be found between the provision that requires legitimation in addition to acknowledgment for granting Japanese nationality, and the legislative purpose mentioned above.

(c) However, since then, along with the changes in social and economic circumstances in Japan, the views regarding family lifestyles, including the desirable way of living together for husband and wife, as well as those regarding parent-child relationships have also varied, and today, the realities of family life and parent-child relationships have changed and become diverse, as seen by the fact that the percentage of children born out of wedlock in the total number of newborn children has been increasing. In combination with these changes in the socially accepted views and social circumstances, as Japan has recently become more international and international exchange has been enhanced, the number of children born to Japanese fathers and non-Japanese mothers has been increasing. In the case of children whose parents are couples of Japanese citizens and foreign citizens, the realities of their family lifestyles (e.g. whether or not the child lives with a Japanese parent) as well as the views regarding a legal marriage and the ideal form of parent-child relationship based thereon are more complicated and diverse than in the case of children whose parents are both Japanese citizens, and in the former case, it is impossible to measure the degree of closeness of the tie between children and Japan just by examining whether or not their parents are legally married. Taking all of these points into consideration, it does not always match up to the realities of family life of today to determine that a child born to a Japanese father and a non-Japanese mother has a close tie with Japan to a sufficient extent for granting him/her Japanese nationality only after the Japanese father became legally married to the non-Japanese mother.

In addition, it seems that other states are moving toward scrapping discriminatory treatment by law against children born out of wedlock, and in fact, the International Covenant on Civil and Political Rights and the Convention on the Rights of the Child, which Japan has ratified, also contain such provisions to the effect that children shall not be subject to discrimination of any kind because of birth. Furthermore, after the provision of Article 3, para. 1 of the Nationality Act was established, many states that had previously required legitimation for granting nationality to children born out of wedlock to fathers who are their citizens have revised their laws in order to grant nationality if, and without any other requirement, it is found that the father-child relationship with their citizens is established as a result of acknowledgement.

In light of these changes in social and other circumstances at home and abroad, we should say that it is now difficult to find any reasonable relevance between the policy of maintaining legitimation as a requirement to be satisfied when acquiring Japanese nationality by making a notification after birth, and the aforementioned legislative purpose.

(d) On the other hand, as explained above, the Nationality Act adopts the principle of jus sanguinis and, while taking a stance of granting Japanese nationality to a child by considering that the existence of a legal parent-child relationship with the father or mother who is a Japanese citizen indicates that the child has a close tie with Japan, provides that a child shall acquire Japanese nationality if the father or mother is a Japanese citizen at the time of birth (Article 2, item 1). As a result, not only a child born in wedlock to a Japanese father or mother but also a child born out of wedlock and acknowledged by a Japanese father before birth and a child born out of wedlock to a Japanese mother are to acquire Japanese nationality by birth, whereas only a child born out of wedlock who is acknowledged by a Japanese father but has not acquired the status of a child born in wedlock as a result of legitimation, although such a child is also born to a Japanese citizen as his/her parent by blood and has a legal parent-child relationship with a Japanese citizen, is unable to acquire Japanese nationality by birth or even by making a notification under Article 3, para. 1 of said Act. We should say that due to such distinction, a child born out of wedlock who satisfies only the requirement of being acknowledged by a Japanese father after birth, alone, is subject to considerable discriminatory treatment in acquiring Japanese nationality.

Considering that acquisition of Japanese nationality means a lot to people in order to enjoy the guarantee of fundamental human rights and other benefits in Japan, we should say that the disadvantages that children would suffer from the above-mentioned discriminatory treatment cannot be overlooked, and we must say that we can hardly find reasonable relevance between such discriminatory treatment and the aforementioned legislative purpose. In particular, between children acknowledged by Japanese fathers before birth and those acknowledged after birth, it is difficult to find a difference in general in terms of the level of the tie with Japanese society developed through their family life with Japanese fathers, and it is also difficult to explain the reasonableness of the policy of applying the above-mentioned distinction when granting Japanese nationality from the perspective of the level of the tie with Japanese society. In addition, under the Nationality Act that adopts the principle of jus sanguinis, if, despite the fact that children born out of wedlock to Japanese mothers can acquire Japanese nationality by birth, children born out of wedlock who satisfy only the requirement of being acknowledged by Japanese fathers after birth are not allowed to acquire Japanese nationality even by making a notification, we should say that such a situation is somewhat inconsistent with the basic stance of the Act from the perspective of gender equality.

(e) The Nationality Act provides that such a child born out of wedlock as mentioned above, although he/she also has a legal parent-child relationship with a Japanese citizen, alone, is not allowed to acquire Japanese nationality by birth or by making a notification unless the marriage of the parents---an act relating to the personal status of the parents that the child can do nothing about---has taken place. If we also take into consideration the circumstances described in (c) and (d) above, we must conclude that in order to achieve the legislative purpose of granting Japanese nationality only to persons who have a close tie with Japan, this provision applies a means that goes far beyond the bounds where reasonable relevance with such legislative purpose can be found, even if the discretionary power vested in the legislative body is taken into account, and as a result, said provision should be deemed to cause unreasonable discrimination.

(f) It is true that there is a way for a child born out of wedlock to a Japanese father and a non-Japanese mother and acknowledged by the father after birth, to acquire Japanese nationality through simplified naturalization prescribed in Article 8, item 1 of the Nationality Act. However, since naturalization depends on the discretion of the Minister of Justice, and even a person who satisfies the requirements prescribed in said item may not automatically acquire Japanese nationality, we cannot deny the lack of reasonable relevance between the Distinction and the aforementioned legislative purpose by regarding simplified naturalization as a substitute for acquisition of Japanese nationality.

We should add that if Japanese nationality is to be granted to a child by reason of acknowledgment by a Japanese father before legitimation takes place, fictitious acknowledgement is likely to occur in an attempt to acquire Japanese nationality. The necessity to prevent acquisition of Japanese nationality by way of a fictitious act may be another reason for the Distinction. However, even though such likelihood exists, the policy of making it a requirement for acquisition of Japanese nationality to acquire the status of a child born in wedlock as a result of the marriage of the parents cannot necessarily be said to have reasonable relevance with the necessity to prevent acquisition of Japanese nationality by way of a fictitious act, and it is difficult to accept this likelihood as a reason to overturn our conclusion mentioned in (e) above.

(3) For the reasons stated above, we should conclude that although the legislative purpose itself from which the Distinction is derived has a reasonable basis, reasonable relevance between the Distinction and the legislative purpose no longer exists due to the changes in social and other circumstances at home and abroad, and today, the provision of Article 3, para. 1 of the Nationality Act imposes an unreasonable and excessive requirement for acquiring Japanese nationality. Moreover, since the Distinction involves another distinction described in (2)(d) above, we must say that it causes a child born out of wedlock who satisfies only the requirement of being acknowledged by a Japanese father after birth to suffer considerably disadvantageous discriminatory treatment in acquiring Japanese nationality, and even if we take into consideration the discretionary power vested in the legislative body when specifying requirements for acquisition of Japanese nationality, we can no longer find any reasonable relevance between the consequence arising from the Distinction and the aforementioned legislative purpose.

Consequently, it can be construed that the Distinction, by the time when the appellant submitted a notification for acquisition of Japanese nationality to the Minister of Justice, at the latest, had lost reasonable relevance with the legislative purpose, even if the discretionary power vested in the legislative body is taken into account.

Therefore, we must conclude that at the time mentioned above, the Distinction amounted to unreasonable discrimination, and the provision of Article 3, para. 1 of the Nationality Act was in violation of Article 14, para. 1 of the Constitution in that the provision caused the Distinction.

５ 本件区別による違憲の状態を前提として上告人に日本国籍の取得を認めることの可否

(1) 以上のとおり，国籍法３条１項の規定が本件区別を生じさせていることは，遅くとも上記時点以降において憲法１４条１項に違反するといわざるを得ないが，国籍法３条１項が日本国籍の取得について過剰な要件を課したことにより本件区別が生じたからといって，本件区別による違憲の状態を解消するために同項の規定自体を全部無効として，準正のあった子（以下「準正子」という。）の届出による日本国籍の取得をもすべて否定することは，血統主義を補完するために出生後の国籍取得の制度を設けた同法の趣旨を没却するものであり，立法者の合理的意思として想定し難いものであって，採り得ない解釈であるといわざるを得ない。そうすると，準正子について届出による日本国籍の取得を認める同項の存在を前提として，本件区別により不合理な差別的取扱いを受けている者の救済を図り，本件区別による違憲の状態を是正する必要があることになる。

[P11] (2) このような見地に立って是正の方法を検討すると，憲法１４条１項に基づく平等取扱いの要請と国籍法の採用した基本的な原則である父母両系血統主義とを踏まえれば，日本国民である父と日本国民でない母との間に出生し，父から出生後に認知されたにとどまる子についても，血統主義を基調として出生後における日本国籍の取得を認めた同法３条１項の規定の趣旨・内容を等しく及ぼすほかはない。

すなわち，このような子についても，父母の婚姻により嫡出子たる身分を取得したことという部分を除いた同項所定の要件が満たされる場合に，届出により日本国籍を取得することが認められるものとすることによって，同項及び同法の合憲的で合理的な解釈が可能となるものということができ，この解釈は，本件区別による不合理な差別的取扱いを受けている者に対して直接的な救済のみちを開くという観点からも，相当性を有するものというべきである。

そして，上記の解釈は，本件区別に係る違憲の瑕疵を是正するため，国籍法３条１項につき，同項を全体として無効とすることなく，過剰な要件を設けることにより本件区別を生じさせている部分のみを除いて合理的に解釈したものであって，その結果も，準正子と同様の要件による日本国籍の取得を認めるにとどまるものである。この解釈は，日本国民との法律上の親子関係の存在という血統主義の要請を満たすとともに，父が現に日本国民であることなど我が国との密接な結び付きの指標となる一定の要件を満たす場合に出生後における日本国籍の取得を認めるものとして，同項の規定の趣旨及び目的に沿うものであり，この解釈をもって，裁判所が法律にない新たな国籍取得の要件を創設するものであって国会の本来的な機能である立法作用を行うものとして許されないと評価することは，国籍取得の要件に関する他の立法上の合理的な選択肢の存在の可能性を考慮したとしても，当を得ないもの [P12] というべきである。

したがって，日本国民である父と日本国民でない母との間に出生し，父から出生後に認知された子は，父母の婚姻により嫡出子たる身分を取得したという部分を除いた国籍法３条１項所定の要件が満たされるときは，同項に基づいて日本国籍を取得することが認められるというべきである。

(3) 原審の適法に確定した事実によれば，上告人は，上記の解釈の下で国籍法３条１項の規定する日本国籍取得の要件をいずれも満たしていることが認められる。そうすると，上告人は，法務大臣あての国籍取得届を提出したことによって，同項の規定により日本国籍を取得したものと解するのが相当である。

5. Whether or not it is permissible to grant Japanese nationality to the appellant on the presupposition of the unconstitutional condition arising from the Distinction

(1) As explained above, we must say that the provision of Article 3, para. 1 of the Nationality Act, in that it causes the Distinction, has been in violation of Article 14, para. 1 of the Constitution since the time mentioned above, at the latest. However, if, just because Article 3, para. 1 of the Nationality Act imposed an excessive requirement for acquiring Japanese nationality and thereby caused the Distinction, the whole part of the provision of Article 3, para. 1 of the Nationality Act is made void in order to eliminate the unconstitutional condition arising from the Distinction, and the chance to acquire Japanese nationality by making a notification is denied even for a child who is legitimated (hereinafter referred to as a "legitimated child"), this would ignore the purpose of said Act that introduced the system for acquisition of Japanese nationality after birth in order to supplement the principle of jus sanguinis, and it can hardly be imagined as the lawmakers' reasonable intention, and therefore we must say that such legal construction is unacceptable. Therefore, it follows that while presupposing the existence of the provision of Article 3, para. 1 of the Nationality Act under which a legitimated child may acquire Japanese nationality by making a notification, it is necessary to give relief to people who are subject to unreasonable discriminatory treatment due to the Distinction, thereby correcting the unconstitutional condition arising from the Distinction.

(2) From this viewpoint, we examine how this problem can be corrected. In light of the demand of equal treatment under Article 14, para. 1 of the Constitution and the basic principle under the Nationality Act, the principle of jus sanguinis, there is no choice but to enforce the provision of Article 3, para. 1 of said Act which allows acquisition of Japanese nationality after birth while keeping the principle of jus sanguinis, in terms of its purpose and content, upon a child born out of wedlock to a Japanese father and a non-Japanese mother who satisfies only the requirement of being acknowledged by the father after birth. In other words, by considering that even such a child is allowed to acquire Japanese nationality by making a notification if he/she satisfies the requirements prescribed in said paragraph except for the requirement of acquiring the status of a child born in wedlock as a result of the marriage of the parents, it may be possible to put a constitutional and reasonable construction on the provision of said paragraph as well as the provisions of said Act, and we should say that such construction is also appropriate from the perspective of opening a path to direct relief for people subject to unreasonable discriminatory treatment due to the Distinction.

The aforementioned construction is drawn by, in order to correct the unconstitutional defect arising from the Distinction, avoiding making void the provision of Article 3, para. 1 of the Nationality Act as a whole and putting a reasonable construction on it while excluding the part that imposes an excessive requirement and causes the Distinction, and the outcome of this construction does not go beyond granting Japanese nationality under the same requirements as those applied to legitimated children. This construction is in line with the purpose and objective of the provision of said paragraph in that it is intended to grant Japanese nationality to a child born out of wedlock after birth if the child satisfies the requirement under the principle of jus sanguinis (having a legal parent-child relationship with a Japanese citizen), and also satisfies other requirements that are the indexes by which to measure the child's close tie with Japan (e.g. the father is currently a Japanese citizen). If it is argued that this construction is impermissible because it is equal to the case where the court creates a new requirement for acquisition of Japanese nationality that is not stipulated by law and performs a legislative act that should originally be performed by the Diet, we should say that such an argument is wrong even if we take into consideration the possibility that there is any other reasonable option for legislation to determine requirements for acquisition of Japanese nationality.

Consequently, we should conclude that a child born out of wedlock to a Japanese father and a non-Japanese mother and acknowledged by the father after birth shall be allowed to acquire Japanese nationality under Article 3, para. 1 of the Nationality Act if the child satisfies the requirements prescribed in said paragraph, except for the requirement of acquiring the status of a child born in wedlock as a result of the marriage of the parents.

(3) According to the facts legally determined by the court of prior instance, we can find that the appellant satisfies all of the requirements prescribed in Article 3, para. 1 of the Nationality Act that should be satisfied based on the legal construction mentioned above. Therefore, it is appropriate to construe that by submitting the notification for acquisition of Japanese nationality to the Minister of Justice, the appellant has acquired Japanese nationality pursuant to the provision of Article 3, para. 1 of the Nationality Act.

６ 結論

以上のとおり，上告人は，国籍法３条１項の規定により日本国籍を取得したものと認められるところ，これと異なる見解の下に上告人の請求を棄却した原審の判断は，憲法１４条１項及び８１条並びに国籍法の解釈を誤ったものである。論旨はこの趣旨をいうものとして理由があり，その余の論旨について判断するまでもなく，原判決は破棄を免れない。そして，以上説示したところによれば，上告人の請求には理由があり，これを認容した第１審判決は結論において是認することができるから，被上告人の控訴を棄却すべきである。

よって，裁判官横尾和子，同津野修，同古田佑紀の反対意見，裁判官甲斐中辰夫，同堀籠幸男の反対意見があるほか，裁判官全員一致の意見で，主文のとおり判決する。なお，裁判官泉徳治，同今井功，同那須弘平，同涌井紀夫，同田原睦夫，同近藤崇晴の各補足意見，裁判官藤田宙靖の意見がある。

6. Conclusion

As mentioned above, the appellant is found to have acquired Japanese nationality pursuant to the provision of Article 3, para. 1 of the Nationality Act. The determination of the court of prior instance, which dismissed the appellant's claim on grounds that are contrary to this reasoning, misconstrues the provisions of Article 14, para. 1 and Article 81 of the Constitution and the provisions of the Nationality Act. The appeal counsel's arguments are well-grounded in alleging such misconstruction, and the judgment of prior instance should inevitably be quashed. According to our holdings shown above, the appellant's claim is well-grounded, and the judgment of first instance that upheld the claim is justifiable, and therefore the appeal to the court of second instance filed by the appellee of final appeal should be dismissed.

Therefore, the judgment has been rendered in the form of the main text by the unanimous consent of the Justices, except that there are a dissenting opinion by Justice YOKOO Kazuko, Justice TSUNO Osamu, and Justice FURUTA Yuki and a dissenting opinion by Justice KAINAKA Tatsuo and Justice HORIGOME Yukio. There are also concurring opinions by Justice IZUMI Tokuji, Justice IMAI Isao, Justice NASU Kohei, Justice WAKUI Norio, Justice TAHARA Mutsuo and Justice KONDO Takaharu, respectively, and an opinion by Justice FUJITA Tokiyasu.

裁判官泉徳治の補足意見は，次のとおりである。

[P13] １ 国籍法３条１項は，日本国民の子のうち同法２条の適用対象とならないものに対する日本国籍の付与について，「父母の婚姻」を要件とすることにより，父に生後認知され「父母の婚姻」がない非嫡出子を付与の対象から排除している。これは，日本国籍の付与に関し，非嫡出子であるという社会的身分と，日本国民である親が父であるという親の性別により，父に生後認知された非嫡出子を差別するものである。

この差別は，差別の対象となる権益が日本国籍という基本的な法的地位であり，差別の理由が憲法１４条１項に差別禁止事由として掲げられている社会的身分及び性別であるから，それが同項に違反しないというためには，強度の正当化事由が必要であって，国籍法３条１項の立法目的が国にとり重要なものであり，この立法目的と，「父母の婚姻」により嫡出子たる身分を取得することを要求するという手段との間に，事実上の実質的関連性が存することが必要である。

２ 国籍法３条１項の立法目的は，父母両系血統主義に基づき，日本国民の子で同法２条の適用対象とならないものに対し，日本社会との密接な結合関係を有することを条件として，日本国籍を付与しようとすることにあり，この立法目的自体は正当なものということができる。

３ 国籍法３条１項は，上記の立法目的を実現する手段として，「父母の婚姻及びその認知により嫡出子たる身分を取得した子」に限って日本国籍を付与することを規定し，父に生後認知された非嫡出子を付与の対象から排除している。

しかし，「父母の婚姻」は，子や日本国民である父の１人の意思では実現することができない要件であり，日本国民を父に持ちながら自己又は父の意思のみでは日本国籍を取得することができない子を作り出すものである。一方，日本国民である [P14] 父に生後認知された非嫡出子は，「父母の婚姻」により嫡出子たる身分を取得していなくても，父との間で法律上の親子関係を有し，互いに扶養の義務を負う関係にあって，日本社会との結合関係を現に有するものである。上記非嫡出子の日本社会との結合関係の密接さは，国籍法２条の適用対象となっている日本国民である母の非嫡出子や日本国民である父に胎児認知された非嫡出子のそれと，それ程変わるものではない。また，父母が内縁関係にあり，あるいは事実上父の監護を受けている場合においては，父に生後認知された非嫡出子の日本社会との結合関係が嫡出子のそれに実質的に劣るものということは困難である。そして，上記非嫡出子は，父の認知を契機として，日本社会との結合関係を発展させる可能性を潜在的に有しているのである。家族関係が多様化しつつある現在の日本において，上記非嫡出子の日本社会との結合関係が，「父母の婚姻」がない限り希薄であるとするのは，型にはまった画一的な見方といわざるを得ない。

したがって，前記の立法目的と，日本国民である父に生後認知された子のうち「父母の婚姻」により嫡出子たる身分を取得したものに限って日本国籍を付与することとした手段との間には，事実上の実質的関連性があるとはいい難い。

結局，国籍法３条１項が日本国籍の付与につき非嫡出子という社会的身分及び親の性別により設けた差別は，強度の正当化事由を有するものということはできず，憲法１４条１項の規定に違反するといわざるを得ない。

４ そして，上告人に対しては，国籍法３条１項から「父母の婚姻」の部分を除いたその余の規定の適用により，日本国籍が付与されるべきであると考える。

国籍法３条１項の主旨は日本国民の子で同法２条の適用対象とならないものに対し日本国籍を付与することにあり，「父母の婚姻」はそのための一条件にすぎない [P15] から，その部分が違憲であるとしても，上記主旨はできる限り生かすのが，立法意思に沿うものというべきである。また，上記のような国籍法３条１項の適用は，「すべての児童は，国籍を取得する権利を有する」ことを規定した市民的及び政治的権利に関する国際規約２４条３項や児童の権利に関する条約７条１項の趣旨にも適合するものである。

ただし，上記のような国籍法３条１項の適用は，国会の立法意思として，「父母の婚姻」の部分を除いたままでは同項を存続させないであろうというがい然性が明白である場合には，許されないと解される。国籍法３条１項から「父母の婚姻」の部分を除くことに代わる選択肢として，まず，同条全体を廃止することが考えられるが，この選択肢は，日本国民である父に生後認知された非嫡出子を現行法以上に差別するものであり，すべての児童が出生や父母の性別により差別されないことを規定した市民的及び政治的権利に関する国際規約２４条及び児童の権利に関する条約２条を遵守すべき日本の国会が，この選択肢を採用することは考えられない。次に，国籍法２条の適用対象となっている日本国民である母の非嫡出子及び胎児認知された非嫡出子についても，「父母の婚姻」という要件を新たに課するという選択肢が考えられるが，この選択肢は，非嫡出子一般をその出生により不当に差別するもので，憲法の平等原則に違反するから，国会がこの選択肢を採用することも考えられない。さらに，「日本で生まれたこと」，「一定期間以上日本に住所を有すること」，「日本国民と生計を一にすること」など，日本社会との密接な結合関係を証するための新たな要件を課するという選択肢が考えられるが，この選択肢は，基本的に法律上の親子関係により日本社会との結合関係を判断するという国籍法の血統主義とは別の観点から要件を付加するもので，国会がこの選択肢を採用するがい [P16] 然性が高いということもできない。結局，国会の立法意思として，「父母の婚姻」の部分を除いては国籍法３条１項をそのまま存続させないであろうというがい然性が明白であるということはできず，「父母の婚姻」の部分を除いて同項を適用し，日本国民である父が生後認知した非嫡出子に日本国籍を付与する方が，立法意思にかなうものと解される。

もとより，国会が，将来において，国籍法３条１項を憲法に適合する方法で改正することは，その立法裁量に属するところであるが，それまでの間は，「父母の婚姻」の部分を除いて同項を適用すべきである。

また，「父母の婚姻」の部分を除いて国籍法３条１項の規定を適用することは，憲法の平等原則の下で同項を解釈し適用するものであって，司法が新たな立法を行うものではなく，司法の役割として当然に許されるところである。

５ 多数意見は，前記差別について，立法目的と手段との間の関連性の点から違憲と解するものであって，基本的な判断の枠組みを共通にするものであり，また，国籍法３条１項の上告人に対する適用についても，前記４と同じ趣旨を述べるものであるから，多数意見に同調する。

The concurring opinion by Justice IZUMI Tokuji is as follows.

1. Article 3, para. 1 of the Nationality Act requires "marriage of the parents" for granting Japanese nationality to children who were born to Japanese citizens as their fathers or mothers and are ineligible for application of Article 2 of said Act, thereby excluding children born out of wedlock who are acknowledged by fathers after birth but who do not satisfy the requirement of "marriage of the parents" from the scope of children eligible to acquire Japanese nationality. This exclusion constitutes discrimination in granting Japanese nationality against children born out of wedlock and acknowledged by Japanese fathers after birth, by reason of their social status as children born out of wedlock and the gender of their Japanese parents, i.e. the fact that it is their fathers (not their mothers) that are Japanese citizens. The interest affected by this discrimination is Japanese nationality, a fundamental legal status, and the reasons for the discrimination are social status and gender, which are indicated as prohibited reasons for discrimination under Article 14, para. 1 of the Constitution. Therefore, in order to determine that this discrimination is not in violation of said paragraph, the legislative purpose of Article 3, para. 1 of the Nationality Act must be important for the State of Japan, and there must be actual and substantial relevance between the legislative purpose and the means to achieve the purpose, i.e. requiring the acquisition of the status of a child born in wedlock as a result of the "marriage of the parents."

2. The legislative purpose of Article 3, para. 1 of the Nationality Act is to, in accordance with the principle of jus sanguinis, grant Japanese nationality to children who were born to Japanese citizens as their fathers or mothers and are ineligible for application of Article 2 of said Act, on condition that they have close connections with Japanese society. This legislative purpose per se can be deemed to be justifiable.

3. Article 3, para. 1 of the Nationality Act, as a means to achieve the legislative purpose mentioned above, provides that Japanese nationality shall be granted only to "a child who has acquired the status of a child born in wedlock as a result of the marriage of the parents and the acknowledgment by either parent," thereby excluding children born out of wedlock and acknowledged by fathers after birth from the scope of children eligible to acquire Japanese nationality.

However, the requirement of "marriage of the parents" cannot be fulfilled by the will of the child or the Japanese father alone, and it gives rise to children who are born to Japanese citizens as their fathers but unable to acquire Japanese nationality by the will of their own or their fathers alone. On the other hand, children born out of wedlock and acknowledged by Japanese fathers after birth, even through they have not acquired the status of a child born in wedlock as a result of the "marriage of the parents," have legal parent-child relationships with their fathers and have the duty to support each other, and in this respect, they actually have connections with Japanese society. The closeness of the connections with Japanese society of such children born out of wedlock is not so different from that of children born out of wedlock to Japanese mothers, who are eligible for application of Article 2 of the Nationality Act, or of children born out of wedlock and acknowledged by Japanese fathers before birth. Furthermore, in the case of children whose parents are in common-law marriage or those who are in effect in the custody of their fathers, it is difficult to say that the connections with Japanese society of children born out of wedlock and acknowledged by Japanese fathers after birth are substantially inferior to such connections of children born in wedlock. In fact, these children born out of wedlock have the potential to develop their connections with Japanese society upon being acknowledged by fathers. In today's Japanese society where family relationships are becoming more diversified, I must say that it is a stereotyped and rigid way of thinking to consider that the connections between the aforementioned children born out of wedlock and Japanese society are weak unless they are supported by the "marriage of the parents."

Consequently, I can hardly find actual and substantial relevance between the aforementioned legislative purpose and the means to achieve this purpose, i.e. granting Japanese nationality only to, among children acknowledged by Japanese fathers after birth, those who have acquired the status of a child born in wedlock as a result of the "marriage of the parents."

In conclusion, the discrimination in granting Japanese nationality created by Article 3, para. 1 of the Nationality Act against children born out of wedlock, which constitutes discrimination by reason of the children's social status and the parent's gender, cannot be deemed to have sufficiently justifiable grounds, and therefore should inevitably be deemed to be in violation of Article 14, para. 1 of the Constitution.

4. I believe that the appellant should be granted Japanese nationality by applying the provision of Article 3, para. 1 of the Nationality Act, except for the part requiring the "marriage of the parents."

The gist of the provision of Article 3, para. 1 of the Nationality Act is to grant Japanese nationality to children who were born to Japanese citizens as their fathers or mothers and are ineligible for application of Article 2 of said Act, and the "marriage of the parents" is merely one of the requirements to be satisfied to achieve this. Therefore, said gist of the provision should be maintained to the greatest possible extent even if the part requiring the "marriage of the parents" is unconstitutional, and this is what the lawmakers would have intended. Furthermore, applying Article 3, para. 1 of the Nationality Act in this manner conforms to the gist of Article 24, para.3 of the Covenant on Civil and Political Rights which provides that "Every child has the right to acquire a nationality" and that of Article 7, para. 1 of the Convention on the Rights of the Child.

However, application of Article 3, para. 1 of the Nationality Act in the manner mentioned above may not be permissible when there is a clear probability that the Diet, from the legislative perspective, will not maintain the provision of said paragraph, with the part requiring the "marriage of the parents" removed therefrom. The most possible alternative to removing the part requiring the "marriage of the parents" from the provision of Article 3, para. 1 of the Nationality Act may be repealing said Article as a whole. However, this option will bring about more serious discrimination than that under the existing Act against children born out of wedlock and acknowledged by Japanese fathers after birth, and it seems unlikely that the Japanese Diet will choose this opinion, despite its obligation to comply with Article 24 of the Covenant on Civil and Political Rights which provides that every child shall be protected from any discrimination as to birth or the parent's gender. The next possible alternative may be also imposing the requirement of "marriage of the parents" on children born out of wedlock to Japanese mothers, who are eligible for application of Article 2 of the Nationality Act, and children born out of wedlock and acknowledged by Japanese fathers before birth. The Diet is also unlikely to choose this option because it will bring about undue discrimination against all children born out of wedlock, which is contrary to the principle of equality under the Constitution. There is also another possible alternative, imposing a new requirement of proving a child's close connections with Japanese society, such as "having been born in Japan," "retaining a domicile in Japan for a certain period of time," or "sharing the same family budget with a Japanese citizen." This option imposes an additional requirement from a viewpoint that is different from the principle of jus sanguinis under the Nationality Act, which determines a child's connections with Japanese society basically from his/her legal parent-child relationship with a Japanese citizen, and therefore it cannot be said to be highly probable that the Diet will choose this opinion. After all, it cannot be said that there is a clear probability that the Diet, from the legislative perspective, will not maintain the provision of Article 3, para. 1 of the Nationality Act, with the part requiring the "marriage of the parents" removed therefrom, and it can be construed that it is more in harmony with the lawmakers' intention to apply the provision of said paragraph, while excluding the part requiring the "marriage of parents," thereby granting Japanese nationality to children born out of wedlock and acknowledged by Japanese fathers after birth.

It is of course within the Diet's legislative discretion to revise, in the future, the provision of Article 3, para. 1 of the Nationality Act in line with the Constitution, but until then, the provision of said paragraph should be applied while excluding the part requiring the "marriage of the parents."

When the court applies the provision of Article 3, para. 1 of the Nationality Act, while excluding the part requiring the "marriage of the parents," it means that the court construes and applies the provision of said paragraph according to the principle of equality under the Constitution, and such application of law is not equal to the creation of a new law by the judiciary but is necessarily permissible as the judiciary's role.

5. The majority opinion construes the aforementioned discrimination to be unconstitutional in terms of the relevance between the legislative purpose and the means to achieve it, and it has a basic framework of judgment in common with my opinion. With regard to application of the provision of Article 3, para. 1 of the Nationality Act to the appellant, the majority opinion is in line with my opinion presented in 4 above. Therefore, I agree with the majority opinion.

裁判官今井功の補足意見は，次のとおりである。

私は，多数意見に同調するものであるが，判示５の点（本件上告人に日本国籍の取得を認めることの可否）についての反対意見にかんがみ，法律の規定の一部が違憲である場合の司法救済の在り方について，私の意見を補足して述べておきたい。

１ 反対意見は，日本国民である父から出生後認知された者のうち，準正子に届出による日本国籍（以下単に「国籍」という。）の取得を認め，そうでない者（以下「非準正子」という。）についてはこれを認める立法をしていないこと（立法不 [P17] 存在ないし立法不作為）が憲法１４条１項に違反するとしても，非準正子にも国籍取得を認めることは，国籍法の定めていない国籍付与要件を判決によって創設するもので，司法権の範囲を逸脱し，許されないとするものである。

２ 裁判所に違憲立法審査権が与えられた趣旨は，違憲の法律を無効とすることによって，国民の権利利益を擁護すること，すなわち，違憲の法律によりその権利利益を侵害されている者の救済を図ることにある。無効とされる法律の規定が，国民に刑罰を科し，あるいは国民の権利利益をはく奪するものである場合には，基本的に，その規定の効力がないものとして，これを適用しないというだけであるから，特段の問題はない。

問題となるのは，本件のようにその法律の規定が国民に権利利益を与える場合である。この場合には，その規定全体を無効とすると，権利利益を与える根拠がなくなって，問題となっている権利利益を与えられないことになる。このように解釈すべき場合もあろう。しかし，国民に権利利益を与える規定が，権利利益を与える要件として，Ａ，Ｂの二つの要件を定め，この両要件を満たす者に限り，権利利益を与える（反対解釈によりＡ要件のみを満たす者には権利利益を与えない。）と定めている場合において，権利利益を与える要件としてＡ要件の外にＢ要件を要求することが平等原則に反し，違憲であると判断されたときに，Ａ要件のみを備える者にも当該権利利益を与えることができるのかが，ここでの問題である。このような場合には，その法律全体の仕組み，当該規定が違憲とされた理由，結果の妥当性等を考慮して，Ｂ要件の定めのみが無効である（すなわちＢ要件の定めがないもの）とし，その結果，Ａ要件のみを満たした者についても，その規定の定める権利利益を与えることになると解することも，法律の合憲的な解釈として十分可能であると考 [P18] える。

３ 国籍法は，父母両系血統主義を採用し，その上に立って，国籍の取得の方法として，[◯１] 出生による当然の取得（２条），[◯２] 届出による取得（３条）及び [◯３] 帰化による取得（４条から９条まで）の三つの方法を定めている。

そして，２条による当然の取得については，出生の時に法律上の父又は母が日本国民であるという要件を備える子は，当然に国籍を取得することを規定している。

次に，３条の届出による取得については，２条の補完規定として，血統上の父は日本国民であるが，非嫡出子として出生し，その後父から認知された子について，準正子に限り国籍取得が認められるとし，非準正子には国籍取得を認めていない。さらに，４条から９条までにおいては，２条及び３条により国籍取得の認められない者について帰化（法務大臣の許可）により国籍取得を認めることとしている。

このような国籍法の定める国籍取得の仕組みを見ると，同法は，法的な意味での日本国民の血統が認められる場合，すなわち法律上の父又は母が日本国民である場合には，国籍取得を認めることを大原則とし，２条はこの原則を無条件で貫き，３条においては，これに父母の婚姻により嫡出子たる身分を取得したことという要件（以下「準正要件」という。）を付加しているということができる。このような国籍法の仕組みからすれば，３条は，血統主義の原則を認めつつ，準正要件を備えない者を除外した規定といわざるを得ない。この点について，反対意見は，３条１項は出生後に日本国民である父から認知された子のうち準正子のみに届出による国籍取得を認めたにすぎず，非準正子の国籍取得については単にこれを認める規定を設けていないという立法不作為の状態が存在するにすぎない旨いうが，国会が同項の規定を設けて準正子のみに届出による国籍取得を認めることとしたことにより，反 [P19] 面において，非準正子にはこれを認めないこととする積極的な立法裁量権を行使したことは明らかである。そして，３条１項が準正子と非準正子とを差別していることが平等原則に反し違憲であるとした場合には，非準正子も，準正子と同様に，国籍取得を認められるべきであるとすることも，上記２のように法律の合憲的な解釈として十分成り立ち得る。

このように考えれば，多数意見は，裁判所が違憲立法審査権を行使して国籍法３条１項を憲法に適合するように解釈した結果，非準正子についても準正子と同様に同項により国籍取得を認められるべきであるとするものであって，同法の定める要件を超えて新たな立法をしたとの非難は当たらない。現行国籍法の下における準正子と非準正子との間の平等原則に違反する差別状態を裁判所が解釈によって解消するには，準正子に与えられた効果を否定するか，非準正子に準正子と同様の効果を与えるしかない。前者の解釈が，その結果の妥当性は別として，立法権を侵害するものではないことには異論はないであろう。これと同様に，後者の解釈を採ることも許容されるというべきである。

私は，以上のような理由により，国籍法３条１項を憲法に適合するように解釈した結果，同項は，日本国民である父から出生後に認知された子は，届出により国籍を取得することができることを認めたものと解するのが相当であり，このように解しても立法権を侵害するものではないと考える。

４ 反対意見によれば，同じく日本国民である父から認知された子であるにもかかわらず，準正子は国籍を取得できるのに，非準正子は司法救済を求めたとしても国籍を取得できないという平等原則に反する違憲の状態が依然として続くことになる。

[P20] 反対意見は，違憲の状態が続くことになっても，立法がない限り，やむを得ないとするものと考えられる。反対意見がそのように解する理由は，憲法１０条が「日本国民たる要件は，法律でこれを定める。」と規定し，いかなる者に国籍を与えるかは国会が立法によって定める事柄であり，国籍法が非準正子に国籍取得を認める規定を設けていない以上，準正子と非準正子との差別が平等原則に反し違憲であっても，非準正子について国籍取得を認めることは，裁判所が新たな立法をすることになり，許されないというものと理解される。

しかし，どのような要件があれば国籍を与えるかについて国会がその裁量により立法を行うことが原則であることは当然であるけれども，国会がその裁量権を行使して行った立法の合憲性について審査を行うのは裁判所の責務である。国籍法３条１項は，国会がその裁量権を行使して行った立法であり，これに対して，裁判所は，同項の規定が準正子と非準正子との間に合理的でない差別を生じさせており，平等原則に反し違憲と判断したのである。この場合に，違憲の法律により本来ならば与えられるべき保護を受けることができない者に対し，その保護を与えることは，裁判所の責務であって，立法権を侵害するものではなく，司法権の範囲を超えるものとはいえない。

５ 非準正子についても国籍を付与するということになれば，国会において，国籍付与の要件として，準正要件に代えて例えば日本国内における一定期間の居住等の他の要件を定めることもできたのに，その裁量権を奪うことになるとする議論もあり得ないではない。そうであっても，裁判所がそのような要件を定めていない国籍法３条１項の合憲的解釈として，非準正子について国籍取得を認めたからといって，今後，国会がその裁量権を行使して，日本国民を父とする生後認知子の国籍取 [P21] 得につき，準正要件に代えて，憲法に適合する要件を定める新たな立法をすることが何ら妨げられるものでないことは，いうまでもないところであり，上記のような解釈を採ることが国会の立法裁量権を奪うことになるものではない。

裁判官那須弘平，同涌井紀夫は，裁判官今井功の補足意見に同調する。

The concurring opinion by Justice IMAI Isao is as follows.

I am in agreement with the majority opinion. However, in light of the dissenting opinion concerning the issue determined by this court as mentioned in 5 above (whether or not it is permissible to grant Japanese nationality to the appellant), I would like to present a concurring opinion with regard to what is a judicial relief that is desired in cases where a provision of a law is partially unconstitutional.

1. The dissenting opinion argues as follows: The Diet, among children acknowledged by Japanese fathers after birth, allows those legitimated to acquire Japanese nationality (hereinafter simply referred to as "nationality") by making a notification but has not yet made a law to grant nationality to those not legitimated (hereinafter referred to as "non-legitimated child(ren)") (this fact can be referred to as non-existence of legislation or inaction on legislation), and even when this violates Article 14, para. 1 of the Constitution, if the courts allows acquisition of nationality by non-legitimated children as well, it is equal to the case where the court, by a judgment, creates a new requirement for granting nationality that is not stipulated in the Nationality Act, and it is beyond the bounds of judicial power and therefore impermissible.

2. The purpose of vesting the court with the power of judicial review on constitutionality is to protect rights and interests of citizens by repealing an unconstitutional law, or in other words, to give relief to people whose rights or interests are infringed by an unconstitutional law. If the provision of a law that is alleged to be void is a provision that imposes a criminal penalty on citizens or deprives citizens of their rights or interests, there is basically no special problem because the issue of unconstitutionality can be solved just by regarding the provision as being ineffective and avoiding its application.

A problem will occur in cases where, as in this law case, the provision of a law in dispute is a provision that grants rights or interests to citizens. In such case, if the provision as a whole is made void, the grounds for granting rights or interests will be lost, which makes it not at all possible to grant the rights or interests concerned. This construction may apply in some cases. However, where the provision to grant rights or interests to citizens specifies two requirements for granting the rights or interests, Requirements A and B, and stipulates that the rights or interests shall be granted only to such persons who satisfy both requirements (which means, as construed in the opposite way, that the rights or interests shall not be granted to those who satisfy only Requirement A), if the court finds it contrary to the principle of equality and therefore unconstitutional to require citizens to satisfy Requirement B in addition to Requirement A in order to acquire the rights or interests, the question would be whether or not it is permissible to grant the rights or interests to those who satisfy only Requirement A. In such case, by taking into consideration various factors such as the framework of the law as a whole, the reason for judging the provision to be unconstitutional, and the appropriateness of the consequences, it can be construed that the part of the provision concerning Requirement B alone should be made void (Requirement B should be ignored), and as a result, those who satisfy only Requirement A are also eligible to acquire the rights or interests granted under the provision, and I think such construction is sufficiently valid as a constitutional construction of law.

3. The Nationality Act adopts the principle of jus sanguinis, and according to this principle, the Act specifies three types of methods of acquiring nationality, (i) automatic acquisition by birth (Article 2), (ii) acquisition by notification (Article 3), and (iii) acquisition by naturalization (Article 4 to Article 9).

Article 2 provides that a child who satisfies the requirement that the legal father or mother is a Japanese citizen at the time of birth shall automatically acquire nationality. Article 3, as a supplementary provision of Article 2, stipulates that a child whose father by blood is a Japanese citizen but who is born out of wedlock and acknowledged by the father after birth may acquire nationality only if the child is legitimated, thereby denying the eligibility of a non-legitimated child to acquire nationality. Article 4 to Article 9 provide a child who is ineligible to acquire nationality under Article 2 or Article 3 with the chance to acquire nationality through naturalization (with permission of the Minister of Justice). The mechanism of the system for acquisition of nationality under the Nationality Act can be summarized as follows: the Act, as a primary principle, provides that nationality shall be granted in cases where a child is found to have a legal blood relationship with a Japanese citizen, or more specifically, where a child's legal father or mother is a Japanese citizen, and Article 2 firmly holds this principle without condition, whereas Article 3 imposes an additional requirement that the child should acquire the status of a child born in wedlock as a result of the marriage of the parents (hereinafter referred to as the "legitimation requirement"). In light of such mechanism under the Nationality Act, I must say that Article 3, while holding the principle of jus sanguinis, excludes children who do not satisfy the legitimation requirement from the scope of eligible children. On this point, the dissenting opinion argues that Article 3, para. 1 only provides that among children acknowledged by Japanese fathers after birth, only those legitimated may acquire nationality by making a notification, whereas with regard to the issue of whether or not to grant nationality to non-legitimated children, the Act has merely failed to have a provision to grant nationality to such children, which amounts to nothing more than inaction of legislation. However, it is obvious that by enacting the provision of Article 3, para. 1 of the Nationality Act and allowing only legitimated children to acquire nationality by making a notification, the Diet has, when viewed from the opposite side, actively exercised its legislative discretion to deny nationality to non-legitimated children. It can be construed that if it is found that Article 3, para. 1 discriminates non-legitimated children from legitimated children, and such discrimination is contrary to the principle of equality and therefore unconstitutional, non-legitimated children should also be granted nationality as legitimated children, and such construction is sufficiently valid as a constitutional construction of law as mentioned in 2 above.

From this viewpoint, the majority opinion can be understood as stating that the court has, by exercising its power of judicial review, tried to construe the provision of Article 3, para. 1 of the Nationality Act in line with the Constitution, and finally reached a conclusion that non-legitimated children should be granted nationality as legitimated children under said paragraph, and such an argument that the court has, by doing so, created a new law beyond the bounds of the requirements stipulated in said Act is a mistaken criticism. If the court, through legal construction, seeks to eliminate the discrimination between legitimated children and non-legitimated children under the existing Nationality Act, which is contrary to the principle of equality, the court has no option but to deny the eligibility of legitimated children or recognize non-legitimated children as being eligible as legitimated children. There may be no objection to the opinion that the former option, irrespective of the validity of its consequence, can never be considered to be infringing the Diet's legislative power. In the same way, the court should also be permitted to choose the latter option.

For the reasons stated above, I believe that based on the constitutional construction of the provision of Article 3, para. 1 of the Nationality Act, it is appropriate to construe that said provision means to allow a child acknowledged by a Japanese father after birth to acquire nationality by making a notification, and this construction does not infringe the Diet's legislative power.

4. Should the dissenting opinion be adopted, the unconstitutional condition that is contrary to the principle of equality would remain---among children acknowledged by Japanese fathers, legitimated children can acquire nationality whereas non-legitimated children cannot acquire nationality even if they go to court for judicial relief.

The dissenting opinion seems to consider that even though the unconstitutional condition is to remain, there is no way to solve this problem unless a legislative measure is taken, on the following grounds: Article 10 of the Constitution provides that "The conditions necessary for being a Japanese national shall be determined by law," and who should be granted nationality is a matter that the Diet should determine through legislation. Since the Nationality Act does not provide that non-legitimated children may acquire nationality, even when the discrimination between legitimated children and non-legitimated children is contrary to the principle of equality and therefore unconstitutional, if the court allows acquisition of nationality by non-legitimated children, it is equal to the case where the court creates a new law and therefore impermissible.

However, although it is needless to say that it is in principle left to the Diet's discretion to take a legislative measure to determine what requirements should be satisfied to grant nationality, it is the court's duty to make a review on the constitutionality of the legislative measure taken by the Diet by exercising its discretionary power. Article 3, para. 1 of the Nationality Act is the legislative measure taken by the Diet by exercising its discretionary power, and the court has examined it and determined that it is contrary to the principle of equality and therefore unconstitutional because the provision of said paragraph causes unreasonable discrimination between legitimated children and non-legitimated children. In such case, it is the court's duty to give protection to people who are prevented by such an unconstitutional law from enjoying protection to which they should have been entitled to enjoy, and such act of the court does not infringe the Diet's legislative power, nor can it be deemed to go beyond the bounds of the court's judicial power.

5. Some people may argue that if the court determines that nationality should also be granted to non-legitimated children, it would derive the Diet of the chance to exercise its discretionary power to add any other requirement for acquisition of nationality in lieu of the legitimation requirement, such as retaining a residence in Japan for a certain period of time, and I do not deny the possibility of such an argument. Nevertheless, even if the court puts a constitutional construction on the provision of Article 3, para. 1 of the Nationality Act, which does not specify such an additional requirement, thereby granting nationality to non-legitimated children, needless to say, this does not preclude the Diet at all from exercising its discretionary power to create a new law that specifies, in lieu of the legitimation requirement, any constitutional requirement to be satisfied by children acknowledged by Japanese fathers after birth in order to acquire nationality, and the aforementioned constitutional construction by the court never deprives the Diet of its discretionary power in legislation.

Justice NASU Kohei and Justice WAKUI Norio support the concurring opinion by Justice IMAI Isao.

裁判官田原睦夫の補足意見は，次のとおりである。

私は，多数意見に賛成するものであるが，国籍の取得と教育を受ける権利等との関係及び胎児認知を受けた者と生後に認知を受けた者との区別の問題に関し，以下のとおり補足意見を述べる。

１ 国籍は，国家の構成員たることを意味するものであり，日本国籍を有する者は，我が国に居住する自由を有するとともに，憲法の保障する基本的人権を享受し，職業を自由に選択し，参政権を行使し，また，法律が国民に認めた各種の権利を行使することができる。

出生又は認知と届出により日本国籍を取得し得るか否かは，国民に認められたそれらの権利を当然に取得し，行使することができるか否かにかかわるものであり，その対象者の人権に直接かかわる事柄である。

認知と届出による国籍の取得は，２０歳未満の者において認められており（国籍法３条１項），また，実際にその取得の可否が問題となる対象者のほとんどは，本件同様，未就学児又は学齢児童・生徒である。したがって，それら対象者においては，国籍の取得により認められる参政権や職業選択の自由よりも，教育を受ける権利や社会保障を受ける権利の行使の可否がより重要である。

憲法２６条は，１項で国民の教育を受ける権利を定め，２項でその裏面として保護者にその子女に対して普通教育を受けさせる義務を定めるとともに，義務教育は [P22] これを無償とする，と定める。そして，この憲法の規定を受けて教育基本法は，国民に，その保護する子に普通教育を受けさせる義務を定め，国又は地方公共団体の設置する学校における義務教育については，授業料を徴収しない，と規定する（旧教育基本法４条，教育基本法５条１項，４項）。また，学校教育法は，保護者に，その子女に対する小学校，中学校への就学義務を定める（平成１９年法律第９６号による改正前の学校教育法２２条，３９条，同改正後の学校教育法１６条，１７条）。そして，学校教育法施行令は，この就学義務を履行させるための事務として，市町村の教育委員会は，当該市町村の住民基本台帳に基づいて，当該市町村の区域内に住所を有する学齢児童及び学齢生徒について学齢簿を編製し，就学予定者の保護者に対し，翌学年の初めから２月前までに小学校又は中学校の入学期日を通知しなければならない（学校教育法施行令１条，５条）等，様々な規定を設けている。これらの規定は，子女の保護者の義務の視点から定められているが，それは，憲法２６条１項の定める当該子女の教育を受ける権利を具現化したものであり，当該子女は，無償で義務教育を受ける権利を有しているのである。ところが，日本国民以外の子女に対しては，それらの規定は適用されず，運用上，市町村の教育委員会が就学を希望する外国人に対し，その就学を許可するとの取扱いがなされているにすぎない。

また，社会保障の関係では，生活保護法の適用に関して，日本国民は，要保護者たり得る（生活保護法２条）が，外国人は同法の適用を受けることができず，行政実務において生活保護に準じて運用されているにすぎないのである。

このように，現行法上，本件上告人のような子女においては，日本国籍を取得することができるか否かにより，教育や社会保障の側面において，その権利を享受で [P23] きるか否かという点で，大きな差異が存するのである。

２ そこで，日本国民である父と日本国民でない母との間で出生し，出生後父から認知をされた子（以下「生後認知子」という。）の国籍取得につき，その父と母が婚姻をして，当該生後認知子が準正子となった場合にのみ認め，それ以外の場合に認めない国籍法３条１項の規定の生後認知子と準正子との取扱いの区別，また，日本国民たる父が胎児認知した場合に当該胎児認知子は当然に国籍を取得する（国籍法２条１号）ことと生後認知子との区別の合理性が，憲法１４条１項に適合するか否かの観点から問題となる。

多数意見は，国籍法３条１項が生後認知子のうち準正子と非準正子を区別することが憲法１４条１項に違反するものとし，国籍法３条１項のうち「父母の婚姻により嫡出子たる身分を取得した」という部分を除いた同項所定の要件が満たされるときは日本国籍を取得することが認められるとするが，その点については全く異論はない。

それとともに，私は，生後認知子における準正子と非準正子との区別の問題と並んで，生後認知子と胎児認知子間の区別の問題も，憲法１４条１項との関係で同様に重要であると考える。

準正子となるか否かは，子の全く与り知らないところで定まるところ，その点においては，胎児認知子と生後認知子との関係についても同様である。しかし，準正の場合は，父母が婚姻するという法的な手続が経られている。ところが，胎児認知子と生後認知子との間では，父の認知時期が胎児時か出生後かという時期の違いがあるのみである。そして，多数意見４(2)エで指摘するとおり，胎児認知子と生後認知子との間においては，日本国民である父の家族生活を通じた我が国社会との結 [P24] び付きの程度に一般的な差異が存するとは考え難く，日本国籍の取得に関して上記の区別を設けることの合理性を我が国社会との結び付きの程度という観点から説明することは困難である。かかる点からすれば，胎児認知子に当然に日本国籍の取得を認め，生後認知子には準正子となる以外に日本国籍の取得を認めない国籍法の定めは，憲法１４条１項に違反するという結論が導かれ得る。

そうして，国籍法３条１項自体を無効と解した上で，生後認知子については，民法の定める認知の遡及効（民法７８４条）が国籍の取得の場合にも及ぶと解することができるならば，生後認知子は，国籍法２条１号により出生時にさかのぼって国籍を取得することとなり，胎児認知子と生後認知子との区別を解消することができることとなる。しかし，このように認知の遡及効が国籍の取得にまで及ぶと解した場合には，認知前に既に我が国以外の国籍を取得していた生後認知子の意思と無関係に認知により当然に国籍を認めることの是非や二重国籍の問題が生じ，さらには遡及的に国籍を認めることに伴い様々な分野において法的問題等が生じるのであって，それらの諸点は，一義的な解決は困難であり，別途法律によって解決を図らざるを得ない事柄である。このように多くの法的な諸問題を生じるような解釈は，国籍法の解釈の枠を超えるものといわざるを得ないのであって，その点からしてかかる見解を採ることはできない。

そうすると，多数意見のとおり国籍法３条１項を限定的に解釈し，２０歳未満の生後認知子は，法務大臣に届け出ることによって日本国籍を取得することができると解することが，同法の全体の体系とも整合し，また，上告人及び上告人と同様にその要件に該当する者の個別救済を図る上で，至当な解釈であると考える。

なお，かかる結論を採る場合，胎児認知子は出生により当然に日本国籍を取得す [P25] るのに対し，生後認知子が日本国籍を取得するには法務大臣への届出を要するという点において区別が存することになるが，生後認知子の場合，上記の二重国籍の問題等もあり，その国籍の取得を生後認知子（その親権者）の意思にゆだねて届出要件を課すという区別を設けることは，立法の合理的裁量の範囲内であって，憲法１４条１項の問題が生じることはないものというべきである。

The concurring opinion by Justice TAHARA Mutsuo is as follows.

I am in agreement with the majority opinion. However, I would like to give my concurring opinion with regard to the issues concerning the relationship between the acquisition of nationality and the right to receive education, and the distinction between children acknowledged before birth and those acknowledged after birth. 1. Having nationality of a certain state means being a member of the state, and people who have Japanese nationality have freedom to reside in Japan, and they are entitled to enjoy the fundamental human rights guaranteed by the Constitution, choose their occupations freely, and exercise their franchise as well as various other rights granted to Japanese citizens by law.

Whether or not a person can acquire Japanese nationality by birth or by acknowledgment and notification makes a difference in whether or not the person can automatically acquire and exercise these rights granted to Japanese citizens, and in this respect, it directly affects the person's human rights.

The chance to acquire nationality by acknowledgment and notification is granted to people aged under 20 (Article 3, para. 1 of the Nationality Act), and in fact, most people who face the issue of eligibility to acquire nationality are preschool children or school-aged children as in this case. Therefore, to these people, among the rights to be granted on condition of acquisition of nationality, whether or not they can exercise the right to receive education or right to receive social security means more than whether they can acquire the franchise or freedom to choose occupations. Article 26 of the Constitution provides for the citizens' right to receive education (para. 1), and also provides for, from the opposite side, guardians' obligation to have their children receive ordinary education, while stipulating that compulsory education shall be free (para.2). In accordance with these provisions of the Constitution, the Fundamental Act of Education provides that citizens shall have the obligation to have children under their protection receive ordinary education, and no tuition fee shall be collected for compulsory education to be provided at schools established by the State or local public entities (Article 4 of the former Fundamental Act of Education Act and Article 5, para. 1 and para.4 of the Fundamental Act of Education). The School Education Act also provides that guardians shall have the obligation to send their children to elementary school and junior high school (Article 22 and Article 39 of the School Education Act prior to revision by Act No. 96 of 2007, Article 16 and Article 17 of the School Education Act after revision). The Ordinance for Enforcement of the School Education Act contains various provisions, such that in order to ensure the performance of the obligation to send children to school, a municipal board of education shall, based on the basic resident register of the municipality, compile student rosters of school-aged students who have domiciles within the area of the municipality, and give a notice to guardians of children who are to reach the school age with regard to the date of admission to elementary school or junior high school, two months before the start of the next academic year (Article 1 and Article 5 of the Ordinance for Enforcement of the School Education Act). These provisions, which are stipulated from the standpoint of the obligation of children's guardians, embody children's right to receive education guaranteed under Article 26, para. 1 of the Constitution, and children accordingly have the right to receive compulsory education without fee. However, these provisions shall not apply to children who do not have Japanese nationality, and their right to receive education is recognized only through the measures taken by individual municipal boards of education to grant admission to foreign children who wish to go to school.

In terms of social security, under the Public Assistance Act, Japanese citizens shall be entitled to public assistance (Article 2 of the Public Assistance Act), whereas foreign nationals shall not be eligible for application of said Act, and they are given assistance equivalent to public assistance only based on administrative decisions.

Thus, under the existing laws, for children like the appellant, whether or not they can acquire Japanese nationality makes a great difference in whether or not they can enjoy benefits of rights to receive education or social security.

2. With regard to the issue of whether or not Japanese nationality should be granted to children born out of wedlock to Japanese fathers and non-Japanese mothers and acknowledged by the fathers after birth (hereinafter referred to as "children acknowledged after birth"), the distinction between non-legitimated children and legitimated children under Article 3, para. 1 of the Nationality Act (children acknowledged after birth shall be granted Japanese nationality only if they are legitimated as a result of the marriage of their parents), and the distinction between children acknowledged by Japanese fathers before birth and those acknowledged after birth (children acknowledged by Japanese fathers before birth shall automatically acquire Japanese nationality under Article 2, item 1 of the Nationality Act) are challenged from the perspective of whether or not they are in conformity to Article 14, para. 1 of the Constitution.

The majority opinion argues that the distinction between legitimated children and non-legitimated children among children acknowledged after birth under Article 3, para. 1 of the Nationality Act is in violation of Article 14, para. 1 of the Constitution, and non-legitimated children may also acquire Japanese nationality if they satisfy the requirements prescribed in Article 3, para. 1 of the Nationality Act, except for the requirement of "having acquired the status of a child born in wedlock as a result of the marriage of the parents." I have no objection to the majority opinion on this point. In addition to the distinction between legitimated children and non-legitimated children among children acknowledged after birth, I consider that the distinction between children acknowledged after birth and those acknowledged before birth is also important in relation to Article 14, para. 1 of the Constitution.

Children can never know whether or not they will be legitimated, and in this respect, there is no difference between children acknowledged before birth and those acknowledged after birth. To become a legitimated child requires a legal procedure, the marriage of the parents. However, the difference between children acknowledged before birth and those acknowledged after birth comes from nothing more than the difference in terms of the time of acknowledgment, whether they are acknowledged before or after birth. As pointed out in 4(2)(d) of the majority opinion, between children acknowledged before birth and those acknowledged after birth, it is difficult to find a difference in general in terms of the level of the tie with Japanese society developed through their family life with Japanese fathers, and it is also difficult to explain the reasonableness of the policy of applying the above-mentioned distinction when granting Japanese nationality from the perspective of the level of the tie with Japanese society. From this standpoint, a conclusion can be drawn that the provision of the Nationality Act that automatically grants Japanese nationality to children acknowledged before birth while not granting Japanese nationality to children acknowledged after birth unless they are legitimated, is in violation of Article 14, para. 1 of the Constitution.

If it is possible to construe, on the assumption that the provision of Article 3, para. 1 of the Nationality Act is void, that the retroactive effectiveness of acknowledgment under the Civil Code (Article 784) also applies to the case of acquisition of nationality, children acknowledged after birth are supposed to acquire Japanese nationality under Article 2, para. 1 of the Nationality Act retroactively as from the time of birth, which will lead to elimination of the distinction between children acknowledged before birth and those acknowledged after birth. However, such construction where the retroactive effectiveness of acknowledgment is also applicable to acquisition of nationality would bring about a question of whether or not it is appropriate to grant nationality by reason of acknowledgement to children acknowledged after birth, who have already acquired nationality of other states before acknowledgment, automatically or regardless of the intention of these children, as well as the problem of dual nationality, and it would also bring about other legal issues in various aspects. It is difficult to solve all of these problems collectively by a single method, but a solution should be sought separately by law. Such a construction that is likely to cause many legal issues should inevitably be deemed to be beyond the construction of the Nationality Act and therefore unacceptable.

Therefore, I believe that the provision of Article 3, para. 1 of the Nationality Act should be construed in a limited manner, as suggested by the majority opinion, so as to construe that children acknowledged after birth who are aged under 20 may acquire Japanese nationality by making a notification to the Minister of Justice, and this construction is consistent with the entire framework of said Act and also reasonable when aiming to give relief on a case-by-case basis to the appellant and other people who also satisfy this requirement.

This conclusion does not completely eliminate the distinction between children acknowledged before birth and those acknowledged after birth in that the former can automatically acquire Japanese nationality by birth whereas the latter are required to make a notification to the Minister of Justice in order to acquire Japanese nationality. However, in the case of children acknowledged after birth, the aforementioned problems such as dual nationality exist, and requiring children acknowledged after birth to make a notification so that the children themselves (or persons who have parental authority over them) can decide whether or not to grant Japanese nationality is within the bounds of reasonable discretion of the legislative body, and such distinction will not raise an issue of violation of Article 14, para. 1 of the Constitution.

裁判官近藤崇晴の補足意見は，次のとおりである。

多数意見は，国籍法３条１項が本件区別を生じさせていることの違憲を宣言するにとどまらず，上告人が日本国籍を取得したものとして，上告人が日本国籍を有することを確認した第１審判決を支持し，これに対する控訴を棄却するものである。

このように，国籍法３条１項の定める要件のうち父母の婚姻により嫡出子たる身分を取得したという部分（準正要件）を除いた他の要件のみをもって国籍の取得を認めることについては，立法府が準正要件に代えて他の合理的な要件を選択する機会を奪うこととなり，立法府に与えられた立法政策上の裁量権を不当に制約するものであって許されないとの批判があり得る。私は，この点に関する今井裁判官の補足意見に全面的に賛同するとともに，多数意見の一員として，更に補足的に意見を述べておきたい。

多数意見は，国籍法３条１項の定める要件のうち準正要件を除いた他の要件のみをもって国籍の取得を認めるのであるが，これはあくまでも現行の国籍法を憲法に適合するように解釈した結果なのであって，国籍法を改正することによって他の要件を付加することが憲法に違反するということを意味するものではない。立法政策上の判断によって準正要件に代わる他の要件を付加することは，それが憲法に適合している限り許されることは当然である。

[P26] 多数意見が説示するように，父母両系血統主義を基調としつつも，日本国民との法律上の親子関係の存在に加え，我が国との密接な結び付きの指標となる一定の要件を設けて，これらを満たす場合に限り出生後における日本国籍の取得を認めることとするという立法目的自体には，合理的な根拠がある。ただ，その目的を達成するために準正を要件とすることは，もはや立法目的との間に合理的関連性を見いだすことができないとしたのである。したがって，国籍法を改正することによって我が国との密接な結び付きの指標となるべき他の要件を設けることは，それが立法目的との間に合理的関連性を有するのであれば，立法政策上の裁量権の行使として許されることになる。例えば，日本国民である父が出生後に認知したことに加えて，出生地が本邦内であること，あるいは本邦内において一定期間居住していることを国籍取得の要件とすることは，諸外国の立法例にも見られるところであり，政策上の当否の点は別として，将来に向けての選択肢にはなり得るところであろう。

また，認知と届出のみを要件とすると，生物学上の父ではない日本国民によって日本国籍の取得を目的とする仮装認知（偽装認知）がされるおそれがあるとして，これが準正要件を設ける理由の一つとされることがあるが，そのようなおそれがあるとしても，これを防止する要請と準正要件を設けることとの間に合理的関連性があるといい難いことは，多数意見の説示するとおりである。しかし，例えば，仮装認知を防止するために，父として子を認知しようとする者とその子との間に生物学上の父子関係が存することが科学的に証明されることを国籍取得の要件として付加することは，これも政策上の当否の点は別として，将来に向けての選択肢になり得ないものではないであろう。

このように，本判決の後に，立法府が立法政策上の裁量権を行使して，憲法に適 [P27] 合する範囲内で国籍法を改正し，準正要件に代わる新たな要件を設けることはあり得るところである。このような法改正が行われた場合には，その新たな要件を充足するかどうかにかかわらず非準正子である上告人が日本国籍を取得しているものとされた本件と，その新たな要件の充足を要求される法改正後の非準正子との間に差異を生ずることになる。しかし，準正要件を除外した国籍法３条１項のその余の要件のみによっても，同項及び同法の合憲的で合理的な解釈が可能であることは多数意見の説示するとおりであるから，準正要件に代わる新たな要件を設けるという立法裁量権が行使されたかどうかによってそのような差異を生ずることは，異とするに足りないというべきである。

The concurring opinion by Justice KONDO Takaharu is as follows.

The majority opinion declares Article 3, para. 1 of the Nationality Act to be unconstitutional in causing the Distinction, and further determines that the appellant has acquired Japanese nationality. In conclusion, the majority opinion supports the judgment of first instance that declared that the appellant has Japanese nationality, while dismissing the appeal to the court of second instance filed against said judgment. The court thus allows acquisition of nationality by excluding, from the requirements prescribed in Article 3, para. 1 of the Nationality Act, the requirement of having acquired the status of a child born in wedlock as a result of the marriage of the parents (legitimation requirement), and only applying the remaining requirements. There may be a criticism that such determination of the court is equal to depriving the legislative body of the opportunity to choose any other reasonable requirement in lieu of the legitimation requirement, thereby unduly restricting the discretionary power vested in the legislative body to take legislative measures, and therefore impermissible. I completely agree with the concurring opinion by Justice IMAI on this point, and as one of the justices who are in agreement with the majority opinion, I would like to give an additional opinion.

The majority opinion allows acquisition of nationality by excluding the legitimation requirements from the requirements prescribed in Article 3, para. 1 of the Nationality Act and applying only the remaining requirements. This is nothing more than the consequence of the court's efforts to construe the existing Nationality Act in line with the Constitution, and it does not mean that revising the Nationality Act to add any other requirement goes against the Constitution. Needless to say, it is permissible to add any other requirement in lieu of the legitimation requirement based on legislative decisions as far as such additional requirement is in conformity to the Constitution.

As explained in the majority opinion, the legislative purpose of the Nationality Act is to, while keeping the principle of jus sanguinis, provide for certain requirements that can be the indicators by which to measure the closeness of the tie between the child and Japan, in addition to the existence of a legal parent-child relationship with a Japanese citizen, and grant Japanese nationality to children after birth only if they satisfy these requirements, and this legislative purpose per se has a reasonable basis. However, the majority opinion holds that no reasonable relevance can be found any longer between requiring legitimation as a means to achieve the legislative purpose and the legislative purpose per se. Therefore, revising the Nationality Act to add any other requirement that can be an indicator to measure the closeness of the tie between the child and Japan is permissible as the exercise of the discretionary power to take legislative measures, as far as such additional requirement has any reasonable relevance with the legislative purpose. For instance, in addition to being acknowledged by a Japanese father after birth, having the place of birth within Japan or residing in Japan for a certain period of time can be a requirement for acquisition of Japanese nationality, as other states also have such requirements, and these options can be chosen in the future, irrespective of whether or not they are acceptable from the policy perspective.

There is an argument that if a person can acquire Japanese nationality just by obtaining acknowledgment and making a notification, a person other than the natural father of a child is likely to make a fictitious acknowledgement (fake acknowledgment) in an attempt to acquire Japanese nationality for the child, and this may be considered as a reason for supporting the legitimation requirement. However, as explained in the majority opinion, even though such likelihood exists, it is difficult to find any reasonable relevance between the necessity to prevent fictitious acknowledgement and the adoption of the legitimation requirement. Nevertheless, in order to prevent fictitious acknowledgment, for instance, making it a requirement for acquisition of nationality to scientifically prove the existence of a natural father-child relationship between the child and the person who is to acknowledge the child, may be another option, and I do not deny the possibility that this option will be chosen in the future, irrespective of whether or not it is acceptable from the policy perspective.

Thus, following the rendition of this judgment, there may be the possibility that the Diet, by exercising its discretionary power to take legislative measures, will revise the Nationality Act in line with the Constitution and provide for an additional requirement in lieu of the legitimation requirement. If such legal revision is made in the future, a difference in treatment would occur between the appellant, who is not legitimated but found to have acquired Japanese nationality regardless of whether or not he/she satisfies the new requirement, and non-legitimated children to be born after the legal revision who are required to satisfy the new requirement. However, since it is possible, as the majority opinion suggests, to put a constitutional and reasonable construction on the provision of Article 3, para. 1 of the Nationality Act as well as the provisions of said Act while taking into consideration only the requirements prescribed under said paragraph except for the legitimation requirement, any possible difference in treatment, which may be caused by the exercise of the discretionary power in legislation to provide for an additional requirement in lieu of the legitimation requirement, will not be so material.

裁判官藤田宙靖の意見は，次のとおりである。

１ 私は，現行国籍法の下，日本国民である父と日本国民でない母との間に生まれた子の間で，同法３条１項が定める「父母の婚姻」という要件（準正要件）を満たすか否かの違いにより，日本国籍の取得に関し，憲法上是認し得ない差別が生じる結果となっていること，この差別は，国籍法の解釈に当たり同法３条１項の文言に厳格にとらわれることなく，同項は上記の準正要件を満たさない者（非準正子）についても適用さるべきものと合理的に解釈することによって解消することが可能であり，また本件においては，当裁判所としてそのような道を選択すべきであること等の点において，多数意見と結論を同じくするものであるが，現行法３条１項が何を定めており，上記のような合理的解釈とは正確にどのようなことを意味するのかという点の理解に関して，多数意見との間に考え方の違いがあることを否定できないので，その点につき意見を述べることとしたい。

２ 現行国籍法の基本構造を見ると，子の国籍の取得については出生時において [P28] 父又は母が日本国民であることを大原則とし（２条），日本国籍を有しない者が日本国籍を取得するのは帰化によることを原則とするが（４条），同法３条１項に定める一定の要件を満たした者については，特に届出という手続によって国籍を取得することができることとされているものというべきである。したがって，同項が準正要件を定めているのは，準正子でありかつ同項の定めるその他の要件を満たす者についてはこれを特に国籍取得の上で優遇する趣旨なのであって，殊更に非準正子を排除しようという趣旨ではない。言い換えれば，非準正子が届出という手続によって国籍を取得できないこととなっているのは，同項があるからではなく，同法２条及び４条の必然的結果というべきなのであって，同法３条１項の準正要件があるために憲法上看過し得ない差別が生じているのも，いわば，同項の反射的効果にすぎないというべきである。それ故また，同項に準正要件が置かれていることによって違憲の結果が生じているのは，多数意見がいうように同条が「過剰な」要件を設けているからではなく，むしろいわば「不十分な」要件しか置いていないからというべきなのであって，同項の合理的解釈によって違憲状態を解消しようとするならば，それは「過剰な」部分を除くことによってではなく，「不十分な」部分を補充することによってでなければならないのである。同項の立法趣旨，そして本件における違憲状態が何によって生じているかについての，上記に述べた考え方に関する限り，私は，多数意見よりはむしろ反対意見と共通する立場にあるものといわなければならない。

３ 問題は，本件における違憲状態を解消するために，上記に見たような国籍法３条１項の拡張解釈を行うことが許されるか否かであって，この点に関し，このような立法府の不作為による違憲状態の解消は専ら新たな立法に委ねるべきであり， [P29] 解釈によってこれを行うのは司法権の限界を超えるものであるという甲斐中裁判官，堀籠裁判官の反対意見には，十分傾聴に値するものがあると言わなければならない。それにもかかわらず，本件において私があえて拡張解釈の道を選択するのは，次のような理由による。

一般に，立法府が違憲な不作為状態を続けているとき，その解消は第一次的に立法府の手に委ねられるべきであって，とりわけ本件におけるように，問題が，その性質上本来立法府の広範な裁量に委ねられるべき国籍取得の要件と手続に関するものであり，かつ，問題となる違憲が法の下の平等原則違反であるような場合には，司法権がその不作為に介入し得る余地は極めて限られているということ自体は否定できない。しかし，立法府が既に一定の立法政策に立った判断を下しており，また，その判断が示している基本的な方向に沿って考えるならば，未だ具体的な立法がされていない部分においても合理的な選択の余地は極めて限られていると考えられる場合において，著しく不合理な差別を受けている者を個別的な訴訟の範囲内で救済するために，立法府が既に示している基本的判断に抵触しない範囲で，司法権が現行法の合理的拡張解釈により違憲状態の解消を目指すことは，全く許されないことではないと考える。これを本件の具体的事情に照らして敷衍するならば，以下のとおりである。

先に見たとおり，立法府は，既に，国籍法３条１項を置くことによって，出生時において日本国籍を得られなかった者であっても，日本国民である父親による生後認知を受けておりかつ父母が婚姻した者については，届出による国籍取得を認めることとしている。このこと自体は，何ら違憲問題を生じるものではなく，同項自体の効力については，全く問題が存在しないのであるから（因みに，多数意見は，同 [P30] 項が「過剰な」要件を設けていると考えることから，本件における違憲状態を理由に同項全体が違憲となる理論的可能性があるかのようにいうが，同項が設けられた趣旨についての上記の私の考え方からすれば，同項自体が違憲となる理論的可能性はおよそあり得ない。），法解釈としては，この条文の存在（立法者の判断）を前提としこれを活かす方向で考えるべきことは，当然である。他方で，立法府は，日本国民である父親による生後認知を受けているが非準正子である者についても，国籍取得につき，単純に一般の外国人と同様の手続を要求するのではなく，より簡易な手続によって日本国籍を取得する可能性を認めている（同法８条）。これらの規定の基盤に，少なくとも，日本国民の子である者の日本国籍取得については，国家の安全・秩序維持等の国家公益的見地からして問題がないと考えられる限り優遇措置を認めようとする政策判断が存在することは，否定し得ないところであろう。そして，多数意見も指摘するとおり，現行法上準正子と非準正子との間に設けられている上記のような手続上の優遇度の違いは，基本的に，前者には我が国との密接な結び付きが認められるのに対し，後者についてはそうは言えないから，との国家公益上の理由によるものと考えられるが，この理由には合理性がなく，したがってこの理由による区別は違憲であるというのが，ここでの出発点なのである。そうであるとすれば，同法３条１項の存在を前提とする以上，現に生じている違憲状態を解消するためには，非準正子についても準正子と同様の扱いとすることが，ごく自然な方法であるということができよう。そして，このような解決が現行国籍法の立法者意思に決定的に反するとみるだけの理由は存在しない。もっとも，立法政策としては，なお，非準正子の中でも特に我が国に一定期間居住している者に限りそれを認める（いわゆる「居住要件」の付加）といったような選択の余地がある，という [P31] 反論が考えられるが，しかし，我が国との密接な結び付きという理由から準正子とそうでない者とを区別すること自体に合理性がない，という前提に立つ以上，何故に非準正子にのみ居住要件が必要なのか，という問題が再度生じることとなり，その合理的説明は困難であるように思われる。このような状況の下で，現に生じている違憲状態を解消するために，同項の対象には日本国民である父親による生後認知を受けた非準正子も含まれるという拡張解釈をすることが，立法者の合理的意思に抵触することになるとは，到底考えられない。

他方で，本件上告人についてみると，日本国籍を取得すること自体が憲法上直接に保障されているとは言えないものの，多数意見が述べるように，日本国籍は，我が国において基本的人権の保障，公的資格の付与，公的給付等を受ける上で極めて重要な意味を持つ法的地位であり，その意味において，基本権享受の重要な前提を成すものということができる。そして，上告人が等しく日本国民の子でありながら，届出によってこうした法的地位を得ることができないでいるのは，ひとえに，国籍の取得の有無に関し現行法が行っている出生時を基準とする線引き及び父母の婚姻の有無による線引き，父母のいずれが日本国民であるかによって事実上生じる線引き等，本人の意思や努力の如何に関わりなく存在する様々の線引きが交錯する中で，その谷間に落ち込む結果となっているが故なのである。仮にこれらの線引きが，その一つ一つを取ってみた場合にはそれなりに立法政策上の合理性を持つものであったとしても，その交錯の上に上記のような境遇に置かれている者が個別的な訴訟事件を通して救済を求めている場合に，先に見たように，考え得る立法府の合理的意思をも忖度しつつ，法解釈の方法として一般的にはその可能性を否定されていない現行法規の拡張解釈という手法によってこれに応えることは，むしろ司法の [P32] 責務というべきであって，立法権を簒奪する越権行為であるというには当たらないものと考える。なお，いうまでもないことながら，国籍法３条１項についての本件におけるこのような解釈が一般的法規範として定着することに，国家公益上の見地から著しい不都合が存するというのであれば，立法府としては，当裁判所が行う違憲判断に抵触しない範囲内で，これを修正する立法に直ちに着手することが可能なのであって，立法府と司法府との間での権能及び責務の合理的配分については，こういった総合的な視野の下に考察されるべきものと考える。

The opinion by Justice FUJITA Tokiyasu is as follows.

1. I am in agreement with the conclusion of the majority opinion on the following points: Under the existing Nationality Act, discrimination in granting Japanese nationality exists among children born out of wedlock to Japanese fathers and non-Japanese mothers depending on whether or not they satisfy the requirement of "marriage of the parents" prescribed in Article 3, para. 1 of said Act (legitimation requirement), and this discrimination is unacceptable under the Constitution; it is possible to eliminate this discrimination by putting a reasonable construction to the provision of Article 3, para. 1 of said Act, without strictly sticking to the exact language of said paragraph, so as to construe that the provision of said paragraph should also be applied to children who do not satisfy the legitimation requirement (non-legitimated children), and in this law case, this court should choose this way. However, I cannot deny that there is a gap between my way of thinking and that of the majority opinion with regard to what the substance of the provision of Article 3, para. 1 of the existing Nationality Act is and what the exact meaning of the aforementioned reasonable construction is. Therefore, I would like to give my own opinion on these points.

2. The basic structure of the existing Nationality Act can be summarized as follows. The Act, as a primary principle, provides that a child shall acquire Japanese nationality if the father or mother is a Japanese citizen at the time of birth (Article 2), and basically allows those who do not have Japanese nationality to acquire Japanese nationality through naturalization (Article 4), while specially allowing acquisition of nationality by those who satisfy the requirements prescribed in Article 3, para. 1 of said Act by making a notification. This means that Article 3, para. 1 of the Act provides for the legitimation requirement with the intention of giving preferential treatment in granting nationality to legitimated children who satisfy other requirements prescribed in said paragraph, and it is not intended to deliberately exclude non-legitimated children. In other words, the present situation where non-legitimated children are unable to acquire nationality by making a notification is not due to the existence of Article 3, para. 1 of the Act but it is rather a natural consequence leading from Article 2 and Article 4 of the Act, and the existence of the discrimination that is caused by the legitimation requirement under Article 3, para. 1 of the Act and cannot be overlooked under the Constitution is, in a way, nothing more than a reflex effect of said paragraph. Accordingly, I should say that the existing unconstitutional condition due to the existence of the legitimation requirement under said paragraph is not derived from the existence of an "excessive" requirement, as argued by the majority opinion, but it is rather caused by the "deficiency" of the requirements, and if we wish to eliminate the unconstitutional condition by putting a reasonable construction to the provision of Article 3, para. 1 of the Act, it should be done not by removing the "excessive" part but by supplementing the "defective" part. As far as my own views shown above with regard to the legislative purpose of said paragraph and the cause of the unconstitutional condition in dispute in this law case are concerned, I must say that I have more in common with the dissenting opinion than with the majority opinion.

3. The question is, in order to eliminate the unconstitutional condition in dispute in this law case, whether or not it is permissible for the court to put a broad construction to the provision of Article 3, para. 1 of the Nationality Act as mentioned above, and with regard to this question, I should say that the dissenting opinion by Justice KAINAKA Tatsuo and Justice HORIGOME Yukio---the unconstitutional condition due to inaction of the legislative body should be eliminated exclusively through a legislative measure to make a new law, and if the court attempts to do so through legal construction, it goes beyond the limit of the judicial power---is sufficiently worth listening to. Nevertheless, I would dare to choose the option of putting a broad construction to solve the issue in this case, for the following reasons.

In general, where the legislative body has been in the state of unconstitutional inaction, the task of eliminating such state should be primarily left to the legislative body, and in particular, as in this law case, where the issue in dispute relates to the requirements and procedure for acquiring nationality, which should by nature be basically left to the legislative body's broad discretion, and the unconstitutional condition at issue is in violation of the principle of equality before the law, it cannot be denied that there is only very limited room for the judiciary to intervene in such inaction. However, where the legislative body has already made a judgment based on a certain legislative policy, and according to the basic direction of such judgment, there seems to be a very limited number of reasonable options to be chosen for the area where a specific legislative measure has not yet been taken, I believe that it is not completely impermissible for the court to, for the purpose of giving relief within the scope of individual lawsuits to people who are subject to seriously unreasonable discrimination, put a reasonable broad construction to the provisions of the existing law and aim to eliminate the unconstitutional condition to the extent that it does not conflict with the basic judgment already made by the legislative body. I would like to explain this reasoning in more detail in light of the specific circumstances of this case.

As mentioned above, the legislative body has, by establishing Article 3, para. 1 of the Nationality Act, already made an arrangement for people who were unable to acquire Japanese nationality upon birth so as to enable them to acquire Japanese nationality by making a notification if they are acknowledged by Japanese fathers after birth and their parents are married. This arrangement itself does not raise any issue of unconstitutionality at all, and there is no problem with the effect of the provision of said paragraph (The majority opinion, considering that said paragraph contains an "excessive" requirement, argues as if there were a theoretical possibility that the provision of said paragraph as a whole would be held unconstitutional due to the unconstitutional condition alleged in this law case. However, according to my views shown above with regard to the legislative purpose of said paragraph, there could be no theoretical possibility that said paragraph itself would be held unconstitutional). It goes without saying that the court should perform legal construction while presupposing the existence of this provision (the lawmakers' judgment) or making good use of it. On the other hand, the legislative body has also made an arrangement for children who are acknowledged by Japanese fathers after birth but not legitimated, not simply requiring them to take the same procedure as foreign nationals in general but allowing them to acquire Japanese nationality through a more simplified procedure (Article 8). It cannot be denied that as the underlying basis for these provisions of the Act, there may be a policy judgment to give preferential treatment at least to children born to Japanese citizens for acquisition of Japanese nationality as far as it will not be problematic from the perspective of national interests, such as ensuring national security and maintaining order. As the majority opinion also points out, the difference in the level of preferential treatment regarding the procedural requirements that exists between legitimated children and non-legitimated children under the existing Act as described above, seems to be basically created because of national interest in that legitimated children seem to have a close tie with Japan whereas non-legitimated children do not. Such grounds are unreasonable and therefore any distinction created due to such grounds is unconstitutional. This is where the argument on unconstitutionality started in this case. Assuming so, and as far as the existence of Article 3, para. 1 of the Nationality Act is presupposed, treating non-legitimated children in the same manner as legitimated children may be a very natural way to eliminate the existing unconstitutional condition. There is no sufficient reason to argue that such solution is absolutely against the intention of the lawmakers who created the existing Nationality Act. A possible counterargument to this view may be that the legislative body could have chosen to grant nationality to, among non-legitimated children, for instance, only those who have been residing in Japan for a certain period of time (add a "residence requirement"). However, since we stand on the assumption that the policy itself of making a distinction between legitimated children and non-legitimated children by reason of the close tie with Japan is unreasonable, a similar question will be posed, why it is necessary to impose the residence requirement only on non-legitimated children, and I find it difficult to give a reasonable explanation to this question. Under these circumstances, when the court, in an effort to eliminate the existing unconstitutional condition, puts a broad construction to the provision of Article 3, para. 1 of the Nationality Act so as to construe that said paragraph shall also apply to non-legitimated children who were acknowledged by Japanese fathers after birth, I cannot possibly think that such legal construction will be in conflict with the lawmakers' reasonable intention.

On the other hand, focusing on the situation of the appellant, it cannot be said that the right to acquire Japanese nationality is directly guaranteed to him/her under the Constitution. However, as stated in the majority opinion, Japanese nationality is an extremely important legal status that means a lot to people in order to enjoy the guarantee of fundamental human rights, obtain public positions or receive public benefits in Japan, and in this respect, it constitutes the critical basis for enjoying fundamental rights. The appellant, despite the fact that he/she was born to a Japanese citizen, is prevented from acquiring such legal status even by making a notification. This is all due to various distinctions made to distinguish people like him/her from others, irrespective of what he/she wishes or how hard he/she tries to avoid--- distinctions made under the existing law to determine whether or not to grant nationality (distinction on the basis of the time of birth and distinction based on whether or not the parents are married), as well as distinction based on the factual cause (distinction based on which of his/her parents (father or mother) is a Japanese citizen), and he/she was caught in a web of these distinctions. Even if these distinctions are reasonable to some extent from the perspective of legislative policy when examined one by one, when people who are in the situation mentioned above due to such web of distinctions demand relief by individually filing lawsuits, it is rather the court's duty to meet such demand by, while taking into consideration the legislative body's reasonable intention that can be presumed, putting a broad construction to the existing provisions of law, which is not generally rejected as an available method of legal construction, and I believe that the court, by doing so, cannot be deemed to go beyond the bound of its power and usurp the legislative power. Needless to add, if any considerable inconvenience would be caused in terms of national interests when the construction on Article 3, para. 1 of the Nationality Act that this court has adopted in this case is established as a general legal rule, the legislative body has a choice to immediately take a legislative measure to revise it to the extent that such measure will not be in conflict with this court's judgment on unconstitutionality. The reasonable sharing of powers and duties between the legislative body and the judicial body should be considered from such comprehensive perspective.

裁判官横尾和子，同津野修，同古田佑紀の反対意見は，次のとおりである。

私たちは，以下の理由により，国籍法が，出生後に認知を受けた子の国籍取得について，準正子に届出による取得を認め，非準正子は帰化によることとしていることは，立法政策の選択の範囲にとどまり，憲法１４条１項に違反するものではなく，上告人の請求を棄却した原審の判断は結論において正当であるから，上告を棄却すべきものと考える。

１ 国籍の付与は，国家共同体の構成員の資格を定めるものであり，多数意見の摘示する諸事情など国家共同体との結び付きを考慮して決せられるものであって，国家共同体の最も基本的な作用であり，基本的な主権作用の一つといえる。このことからすれば，国籍付与の条件をどう定めるかは，明確な基準により，出生時において，一律，かつ，可能な限り単一に取得されるべきことなどの要請を害しない範囲で，広い立法裁量にゆだねられているというべきである。

国籍が基本的人権の保障等を受ける上で重要な法的地位であるとしても，特定の国の国籍付与を権利として請求することは認められないのが原則であって，それによって上記裁量が左右されるものとはいえない。また，無国籍となるような場合は [P33] 格別，いずれの国の保障を受けるか，例えば我が国の保障を受けるか，それとも他国の保障を受けるかということは，各国の主権にかかわることであり，法的な利益・不利益も，それぞれの国籍に応じて，居住国あるいは事柄によって相違し，時には反対にもなり得る相対的なものであることも考慮すべきである。

なお，いわゆる多重国籍は，国籍が出生時に一律に付与されることから不可避的に生じる事態であって，やむを得ないものとして例外的に容認されているものにとどまる。

国籍法は，血統主義を基調としながらも，出生時において，血統のみならず，法的にも日本国民の子である者に対して，一律に国籍を付与する一方で，日本国民の血統に属する子が出生後に法的に日本国民の子となった場合には，出生後の生活状況が様々であることから，日本国民の子であることを超えた我が国社会との結び付きの有無，程度を具体的に考慮して国籍を付与するかどうかを決することとしていると解される。

このような国籍法の体系から見れば，同法３条１項の規定は，国籍の当然取得の効果を認める面では同法２条の特別規定である一方，出生後の国籍取得という面では帰化の特別規定としての性質を持つものといえる。

２ 多数意見は，出生後の国籍取得を我が国との具体的な結び付きを考慮して認めることには合理性があり，かつ，国籍法３条１項の立法当時は，準正子となることをもって密接な結び付きを認める指標とすることに合理性があったとしながらも，その後における家族生活や親子関係に関する意識の変化，非嫡出子の増加などの実態の変化，日本国民と外国人との間に生まれる子の増加，諸外国における法制の変化等の国際的動向などを理由として，立法目的との関連において準正子となっ [P34] たことを結び付きを認める指標とする合理性が失われたとする。

しかしながら，家族生活や親子関係に関するある程度の意識の変化があることは事実としても，それがどのような内容，程度のものか，国民一般の意識として大きな変化があったかは，具体的に明らかとはいえない。

実態の変化についても，家族の生活状況に顕著な変化があるとは思われないし，また，統計によれば，非嫡出子の出生数は，国籍法３条１項立法の翌年である昭和６０年において１万４１６８人（１．０％），平成１５年において２万１６３４人（１．９％）であり，日本国民を父とし，外国人を母とする子の出生数は，統計の得られる昭和６２年において５５３８人，平成１５年において１万２６９０人であり，増加はしているものの，その程度はわずかである。

このように，約２０年の間における非嫡出子の増加が上記の程度であることは，多数意見の指摘と異なり，少なくとも，子を含む場合の家族関係の在り方については，国民一般の意識に大きな変化がないことの証左と見ることも十分可能である。

確かに，諸外国においては，西欧諸国を中心として，非準正子についても国籍取得を認める立法例が多くなったことは事実である。しかし，これらの諸国においては，その歴史的，地理的状況から国際結婚が多いようにうかがえ，かつ，欧州連合（ＥＵ）などの地域的な統合が推進，拡大されているなどの事情がある。また，非嫡出子の数も，３０％を超える国が多数に上り，少ない国でも１０％を超えているようにうかがわれるなど，我が国とは様々な面で社会の状況に大きな違いがある。

なお，国籍法３条１項立法当時，これらの国の法制が立法政策としての相当性については参考とされたものの，憲法適合性を考える上で参考とされたようにはうかがえない。このようなことからすれば，これらの諸国の動向を直ちに我が国における [P35] 憲法適合性の判断の考慮事情とすることは相当でないと考える。

また，多数意見は，日本国民が母である非嫡出子の場合，あるいは胎児認知を受けた場合との差も指摘する。

しかし，これらの場合は，出生時において法的に日本国民の子であることが確定しているのであって，その後の生活状況の相違が影響する余地がない一方，国籍は，出生時において，一律に付与される必要があることからすれば，これらの子にも国籍を付与することに合理性がある。実質的に見ても，非嫡出子は出生時において母の親権に服すること，胎児認知は任意認知に限られることなど，これらの場合は，強弱の違いはあっても，親と子の関係に関し，既に出生の時点で血統を超えた我が国社会との結び付きを認めることができる要素があるといえる。また，母が日本国民である場合との差は，出生時における子との種々のかかわり合いに関する父と母の違いから生じるもので，これを男女間における差別ととらえることは相当とは思われない。

３ 一方，国籍法３条１項は，婚姻と出生の前後関係が異なる場合における国籍取得の均衡を図るとともに，親と生活関係を共にする未成年の嫡出子は親と同一の国籍に属することが望ましいという観点も考慮して立法されたものであり，その意味で出生時を基準とする血統主義を補完する措置とされるものであって，血統主義の徹底，拡充を図ることを目的とするものではない。そして，準正により父が子について親権者となり，監護，養育の権利，義務を有することになるなど，法律上もその関係が強固になること，届出のみにより国籍を付与する場合，その要件はできるだけ明確かつ一律であることが適当であること，届出による国籍取得は，外国籍からの離脱が条件とされていないこと，非準正子の場合は，我が国との結び付きの [P36] 有無，程度が様々であるから，これを個別，具体的に判断する帰化制度によることが合理的で国籍法の体系に沿うものであるところ，帰化の条件が大幅に緩和されていることなどからすれば，認知を受けた場合全般ではなく，準正があった場合をもって届出により国籍取得を認めることとすることには十分合理性が認められるのであって，これらの点が多数意見指摘の事情によって変化したとはいえない。

なお，多数意見は，帰化について，認知を受けた子に関しては帰化の条件が緩和されているとしても，帰化が法務大臣の裁量によるものであって，準正子と非準正子との差を合理的なものとするものではないとする。しかし，類型的に我が国社会との結び付きを認めることが困難な非準正子については，帰化によることが合理的なことは前記のとおりであるし，また，裁量行為であっても，国家機関として行うものである以上，制度の趣旨を踏まえた合理的なものでなければならず，司法による審査の対象ともなり得るものであり，その運用について考慮すべき点があるとしても，多数意見は，国籍法の体系及び簡易帰化の制度を余りにも軽視するものといわざるを得ない。

以上からすれば，非準正子についても我が国との密接な結び付きを認めることが相当な場合を類型化して国籍取得を認めるなど，届出による国籍取得を認める範囲について考慮する余地があるとしても，国籍法が，準正子に届出による国籍の取得を認め，非準正子は帰化によることとしていることは，立法政策の選択の範囲にとどまり，憲法１４条１項に違反するものではないと考える。

もとより，私たちも，これらの子についても，必要に応じて，適切な保護等が与えられるべきことを否定するものではない。しかし，そのことと国籍をどのような条件で付与するかは，異なる問題である。

[P37] ４ なお，仮に非準正子に届出による国籍の取得を認めないことが違憲であるとしても，上告を棄却すべきものと考える。その理由は，甲斐中裁判官，堀籠裁判官の反対意見とおおむね同旨であるが，以下の点を付加して述べておきたい。

両裁判官指摘のとおり，非準正子が届出により国籍を取得することができないのは，これを認める規定がないからであって，国籍法３条１項の有無にかかわるものではない。同項は，認知を受けたことが前提となるものではあるが，その主体は嫡出子の身分を取得した子であり，その範囲を準正によりこれを取得した場合としているものである。

多数意見は，国籍法が血統主義を基調とするもので，同項に関し，上記の前提があることを踏まえ，準正子に係る部分を除くことによって，認知を受けた子全般に同項の効果を及ぼそうとするもののようにうかがえる。しかし，準正子に係る部分を取り除けば，同項はおよそ意味不明の規定になるのであって，それは，単に文理上の問題ではなく，同項が専ら嫡出子の身分を取得した者についての規定であることからの帰結である。認知を受けたことが前提になるからといって，準正子に係る部分を取り除けば，同項の主体が認知を受けた子全般に拡大するということにはいかにも無理がある。また，そのような拡大をすることは，条文の用語や趣旨の解釈の域を越えて国籍を付与するものであることは明らかであり，どのように説明しようとも，国籍法が現に定めていない国籍付与を認めるものであって，実質的には立法措置であるといわざるを得ない。

また，多数意見のような見解により国籍の取得を認めることは，長年にわたり，外国人として，外国で日本社会とは無縁に生活しているような場合でも，認知を受けた未成年者であれば，届出さえすれば国籍の取得を認めることとなるなど，我が [P38] 国社会との密接な結び付きが認められないような場合にも，届出による国籍の取得を認めることとなる。届出の時に認知をした親が日本国民であることを要するとしても，親が日本国籍を失っている場合はまれであり，そのことをもって，日本国民の子であるということを超えて我が国との密接な結び付きがあるとするのは困難であって，実質は，日本国籍の取得を求める意思（１５歳未満の場合は法定代理人の意思）のみで密接な結び付きを認めるものといわざるを得ない。

このようなことは，国籍法３条１項の立法目的を大きく超えることとなるばかりでなく，出生後の国籍取得について我が国社会との密接な結び付きが認められることを考慮すべきものとしている国籍法の体系ともそごするものである。

なお，国籍付与の在り方は，出入国管理や在留管理等に関しても，様々な面で大きな影響を及ぼすものであり，そのような点も含めた政策上の検討が必要な問題であることも考慮されるべきである。

仮に多数意見のような見解が許されるとすれば，創設的権利・利益付与規定について，条文の規定や法律の性質，体系のいかんにかかわらず，また，立法の趣旨，目的を超えて，裁判において，法律が対象としていない者に，広く権利，利益を付与することが可能となることになる。

私たちは，本件のような場合についても，違憲立法審査権が及ぶことを否定するものではない。しかしながら，上記の諸点を考慮すれば，本件について，裁判により国籍を認めることは，司法権の限界との関係で問題があると考える。

The dissenting opinion by Justice YOKOO Kazuko, Justice TSUNO Osamu, and Justice FURUTA Yuki is as follows.

The Nationality Act provides that among children acknowledged after birth, legitimated children are allowed to acquire Japanese nationality by making a notification whereas non-legitimated children are required to follow the naturalization procedure, and we believe that these provisions are not beyond the range of choices of legislative policy and therefore not in violation of Article 14, para. 1 of the Constitution. Consequently, we find that the conclusion of the court of prior instance that dismissed the appellant's claim is justifiable, and his/her final appeal should be dismissed. The reasons for our opinion are as follows. 1. To grant nationality is to determine a person's status as a member of a national community, and whether or not to grant nationality should be decided by taking into consideration the person's tie with the national community and other various circumstances as indicated by the majority opinion. It is the most fundamental function of a national community and can be said to be one of the most fundamental sovereign functions. From this viewpoint, we should say that it is left to the broad legislative discretion to formulate requirements for granting nationality, to the extent not prejudicial to the principle that nationality should be granted according to clear standards upon birth uniformly and in the manner that each person should have only one nationality if possible. Although nationality is an important legal status necessary to enjoy the protection of fundamental human rights and other benefits, it is unallowable, in principle, to claim nationality of a particular state as a right, and such importance of nationality cannot be deemed to have any influence on the aforementioned legislative discretion. It should also be noted that, apart from the case where a person has no nationality at all, in which state a person receives protection, in Japan or any other state, is an issue of the sovereignty of each state. Legal advantages or disadvantages that the person is to enjoy or suffer will vary depending on his/her respective nationality or state of residence or depending on the issue in question, and such advantages and disadvantages are of a relative nature, i.e. an advantage in one state could be a disadvantage in another state and vice versa.

Dual nationality is a condition that arises unavoidably from the fact that nationality is granted uniformly upon birth, and it is only acceptable as an inevitable exception.

The Nationality Act, while keeping the principle of jus sanguinis, grants nationality uniformly upon birth to people who are children of Japanese citizens not only by blood but also by law, and it can be construed to provide that in cases where children who have blood relationships with Japanese citizens have become legal children of Japanese citizens after birth, since such children have different living conditions, whether or not to grant nationality should be determined by specifically examining whether or not the children have a tie with Japanese society that is beyond the mere fact that they were born to Japanese citizens, and considering the degree of closeness of such tie.

In light of such structure of the Nationality Act, the provision of Article 3, para. 1 of said Act can be regarded as a special provision of Article 2 of said Act in that it recognizes the effect of automatic acquisition of nationality, and at the same time it can also be regarded as a special provision on naturalization in that it allows acquisition of nationality after birth.

2. The majority opinion argues as follows. Although it is reasonable to allow acquisition of nationality after birth by taking into consideration a child's tie with Japan, and at the time when Article 3, para. 1 of the Nationality Act was enacted, it was reasonable to regard the fact of becoming a legitimated child as an indicator to show the existence of a close tie between the child and Japan. However, due to the changes that have occurred since then, such as changes in views regarding family lifestyles and parent-child relationships, changes in the realities such as the increase in the number of children born out of wedlock, the increase in the number of children born to couples of Japanese citizens and foreign citizens, and the changes in international trends in legal systems, it is no longer reasonable, in relation to the legislative purpose, to regard the fact of legitimation as an indicator to show the child's tie with Japan.

However, although it is true that the views regarding family lifestyles and parent-child relationships have changed to some extent, in what form and to what extent these views have changed, or whether or not there has been a significant change in the public consciousness of these matters, cannot be deemed to be specifically clarified.

We do not think that there has been an outstanding change in the realities of family lifestyles. According to the statistics, the number of children born out of wedlock increased from 14,168 (1.0%) in 1985, the year following the year of enactment of Article 3, para. 1 of the Nationality Act, to 21,634 (1.9%) in 2003, and the number of children born to Japanese fathers and foreign mothers also increased from 5,538 in 1987, the first year when statistical data were available, to 12,690 in 2003, but the increase in these numbers is small.

Thus, contrary to the argument presented by the majority opinion, it is sufficiently possible to regard the fact that the increase in the number of children born out of wedlock over the past 20 years is so small, as proof to show, at least, that there has been no significant change in the public consciousness with regard to the desirable form of a family with a child.

It is true that foreign states, mainly those in Western Europe, have made laws to grant nationality to non-legitimated children as well as legitimated children. However, in these states, it seems that international marriages have been popular for historical or geographical reasons, and in addition, regional integration has been promoted and enhanced, as seen in the case of formation of the European Union. Furthermore, the percentage of children born out of wedlock exceeds 30% in many of these states, and even in the lower cases, the percentage seems to exceed 10%. Thus, there is a large difference between these states and Japan in terms of the social circumstances. At the time of enactment of Article 3, para. 1 of the Nationality Act, the legal systems of these foreign states may have been referred to when examining whether the provision of said paragraph was appropriate as a legislative measure but they do not seem to have been referred to when examining the constitutionality of said provision. According to these circumstances, we consider that it is inappropriate to directly take into consideration the trends in these foreign states in the process of examining the constitutionality of the provision in Japan.

The majority opinion also points out the difference in treatment compared to children born out of wedlock to Japanese mothers or children acknowledged by Japanese fathers before birth.

However, in both cases, it is determined at the time of birth that the children are legal children of Japanese citizens, and there is no possibility that any subsequent change in their living situation will have an influence on this definite fact. Considering that nationality should be granted uniformly upon birth, it is reasonable to grant Japanese nationality to these children. Substantially, children born out of wedlock to Japanese mothers shall be subject to the parental authority of the mother upon birth, and acknowledgment before birth may be made only voluntarily. In these cases, although there may be a difference in level, we can find some factors showing that children, upon birth, already have a tie with Japanese society arising from the parent-child relationship, which is stronger than the tie established by blood. The difference in treatment between children born out of wedlock to Japanese fathers and those to Japanese mothers arises from the difference between father and mother in terms of how they interact with the child upon birth, and we do not find it appropriate to regard such difference as discrimination based on gender.

3. On the other hand, Article 3, para. 1 of the Nationality Act was enacted with the aim of achieving a balance in treatment, when granting nationality, between children whose birth precedes the marriage of the parents and children whose birth follows the marriage of the parents, and also by giving consideration to the view that it is desirable that children born in wedlock aged under 20 who live with their parents should have the same nationality as that of the parents. In this respect, said paragraph is established as a measure to supplement the principle of jus sanguinis, under which nationality is granted on the basis of the time of birth, and it is not intended to thoroughly implement or enhance the principle of jus sanguinis. We can find it sufficiently reasonable to allow acquisition of nationality not in all cases where children have obtained acknowledgement but only in cases where legitimation has occurred and legitimated children have made a notification. There are various reasons supporting this view: (i) When legitimation has occurred, the legal relationship between the father and the child becomes firm because the father obtains the parental authority over the child and is also given the rights and obligations to take custody of and take care of the child; (ii) If nationality shall be granted on the sole condition of making a notification, the requirements for such notification should be made as clear and uniform as possible; (iii) A person who wishes to acquire nationality by making a notification is not required to renounce his/her own nationality in a foreign state; (iv) Since non-legitimated children have different levels of ties with Japan, it is reasonable and consistent with the structure of the Nationality Act to apply to them the naturalization procedure wherein the level of tie with Japan is examined specifically on a case-by-case basis; and (v) in the case of non-legitimated children, the requirements for naturalization are significantly relaxed. It cannot be said that these points have been changed due to the circumstances suggested by the majority opinion.

With regard to naturalization, the majority opinion argues that even though the requirements for naturalization are relaxed for children who have obtained acknowledgement, naturalization depends on the discretion of the Minister of Justice, and the availability of the naturalization procedure does not give reasonable grounds for the difference in treatment between legitimated children and non-legitimated children. However, as explained above, with regard to non-legitimated children whose ties with Japanese society are difficult to classify, it is rather reasonable to grant them nationality through naturalization. Furthermore, even though naturalization depends on a discretionary act of the Minister of Justice, as far as the minister performs this act as a State organ, the act should be reasonable based on the purpose of the naturalization system, and may also be subject to a judicial review. We must say that the majority opinion underestimates the entire structure of the Nationality Act and the simplified naturalization system, although there may be some points to consider in the operation thereof.

For the reasons stated above, we believe that even though there is room to review the scope of children eligible to acquire nationality by making a notification through arrangements such as classifying the cases where a close tie with Japan can be found in non-legitimated children, the provisions of the Nationality Act which allow legitimated children to acquire nationality by making a notification, while requiring non-legitimated children to follow the naturalization procedure, are not beyond the range of choices of legislative policy and therefore not in violation of Article 14, para. 1 of the Constitution.

We of course do not deny that non-legitimated children should be given proper protection depending on their needs, but it is a diffident matter from on what conditions nationality should be granted.

4. Even supposing that it is unconstitutional not to allow non-legitimated children to acquire nationality by making a notification, we still believe that the final appeal should be dismissed. The reasons for our view are almost the same as the dissenting opinion by Justice KAINAKA Tatsuo and Justice HORIGOME Yukio. We would like to make an additional comment on this point.

As both Justice KAINAKA and Justice HORIGOME suggest, the impossibility for non-legitimated children to acquire nationality even by making a notification is due to lack of a provision that allows their acquisition of nationality, and it is the same with or without the provision of Article 3, para. 1 of the Nationality Act. Although said provision requires acknowledgment as a prerequisite for acquiring nationality, it mainly focuses on children who have acquired the status of a child born in wedlock, and limits the scope of children eligible to receive nationality to those who have acquired such status as a result of legitimation.

It appears that the majority opinion, while considering that the Nationality Act keeps the principle of jus sanguinis and that Article 3, para. 1 of said Act provides for the aforementioned prerequisite, intends to make the provision of said paragraph effective for all children who have obtained acknowledgement, by removing the part pertaining to legitimated children. However, the provision of said paragraph, if the part pertaining to legitimated children is removed therefrom, would be almost meaningless, and it is not an issue of literal construction but is a consequence of the fact that said provision exclusively targets children who have acquired the status of a child born in wedlock. It is indeed unreasonable to consider, just because acknowledgment is the prerequisite for acquiring nationality, that the removal of the part pertaining to legitimated children will expand the scope of children subject to said provision to all children who have obtained acknowledgement. Furthermore, it is obvious that expanding the scope of eligible children in such manner amounts to granting nationality beyond the bounds of construction of the terms and purport of the provisions of the Act, and whatever explanation is given, we must say that such expansion is equal to allowing acquisition of nationality in cases that are not actually stipulated in the Nationality Act and in effect constitutes a legislative measure.

In addition, if acquisition of nationality is allowed according to the view suggested by the majority opinion, it would lead to the consequence that even a person who has been living in a foreign state as a foreign national over many years without having any relations with Japanese society can acquire Japanese nationality just by making a notification if the person is a minor and has obtained acknowledgment, or in other words, acquisition of Japanese nationality would be allowed even in cases where no close tie can be found between children and Japanese society. Although there is a requirement that the parent who has acknowledged the child should be a Japanese citizen at the time when the child makes a notification, since it is rare that such parent has lost Japanese nationality by the time of notification, it is difficult to show, just because said requirement is satisfied, that the child has a close tie with Japan that is beyond the mere fact that the child was born to a Japanese citizen, and we must say that the arrangement as suggested by the majority opinion is in effect the same as recognizing the child's close tie with Japan just by reason of the child's intention to seek Japanese nationality (or in the case of a child aged under 15, such intention of the child's statutory agent).

Such view according to the majority opinion is not only far beyond the legislative purpose of Article 3, para. 1 of the Nationality Act but also inconsistent with the structure of the Nationality Act wherein whether the child has a close tie with Japanese society should be taken into consideration when granting nationality after birth.

The procedure for granting nationality has a significant impact in various aspects with regard to immigration control and management of foreign nationals residing in Japan, and it should be noted that it is an issue that needs to be examined from a policy perspective by taking these matters into consideration.

Should the view suggested by the majority opinion be acceptable at all, in cases where the provisions for granting rights or interests created by laws are concerned, it would be possible for the court to grant a wide range of such rights or interests to people who are not entitled to receive them under the laws, regardless of the content of the provisions or the nature or structure of the laws, and beyond the legislative purpose or objective thereof. We do not mean to deny that the court may exercise its power of judicial review on constitutionality in cases like this law case. However, taking into consideration all of these points mentioned above, we believe that if the court grants nationality by a judicial decision in this case, it would cause a problem in terms of the limit of the judicial power.

裁判官甲斐中辰夫，同堀籠幸男の反対意見は，次のとおりである。

私たちは，本件上告を棄却すべきものと考えるが，その理由は次のとおりである。

[P39] １ 国籍法は，憲法１０条の規定を受け，どのような要件を満たす場合に，日本国籍を付与するかということを定めた創設的・授権的法律であ閨C国籍法の規定がなければ，どのような者が日本国民であるか定まらないのである。国籍法が日本国籍を付与するものとして規定している要件に該当しない場合は，日本国籍の取得との関係では，白紙の状態が存在するにすぎない。すなわち，日本国籍を付与する旨の規定を満たさない場合には，国籍法の規定との関係では，立法の不存在ないし立法不作為の状態が存在するにすぎないのである。このことは，国会が政策的見地から，国民に対し，一定の権利・利益を付与することとしている創設的・授権的な行政関係の法律の場合も，同様である。

２ 国籍法２条１号によれば，日本国民たる父が胎児認知した子は，生来的に日本国籍を取得することとなる。また，同法は，３条１項において，父が日本国民である準正子は届出により日本国籍を取得する旨定める。しかし，出生後認知された者であって準正子に当たらない者（非準正子）については，同法は，届出により日本国籍を付与する旨の規定を置いていないのであるから，非準正子の届出による国籍取得との関係では，立法不存在ないし立法不作為の状態が存在するにすぎないというべきである。

３ 国籍法が，準正子に対し，届出により国籍を付与するとしながら，立法不存在ないし立法不作為により非準正子に対し届出による国籍付与のみちを閉じているという区別（以下「本件区別」という。）は，３条１項が制定された当時においては合理的な根拠があり，憲法１４条１項に違反するものではないが，遅くとも，上告人が法務大臣あて国籍取得届を提出した当時には，合理的な理由のない差別となっており，本件区別は同項に違反するものであったと考える。その理由は，多数意 [P40] 見が４で述べるところと同様である。しかしながら，違憲となるのは，非準正子に届出により国籍を付与するという規定が存在しないという立法不作為の状態なのである。多数意見は，国籍法３条１項の規定自体が違憲であるとするものであるが，同規定は，準正子に届出により国籍を付与する旨の創設的・授権的規定であって，何ら憲法に違反するところはないと考える。多数意見は，同項の規定について，非準正子に対して日本国籍を届出によって付与しない趣旨を含む規定であり，その部分が違憲無効であるとしているものと解されるが，そのような解釈は，国籍法の創設的・授権的性質に反するものである上，結局は準正子を出生後認知された子と読み替えることとなるもので，法解釈としては限界を超えているといわざるを得ない。

もっとも，特別規定や制限規定が違憲の場合には，その部分を無効として一般規定を適用することにより権利を付与することは法解釈として許されるといえよう。

しかしながら，本件は，そのような場合に当たらないことは明らかである。国籍法は，多数意見が述べるように，原則として血統主義を採っているといえるが，徹底した血統主義を法定していると解することはできないのであるから，３条１項の規定について，出生後認知された子に対し届出による日本国籍を付与することを一般的に認めた上で，非準正子に対し，その取得を制限した規定と解することはできない。

したがって，国籍法３条１項の規定の解釈から非準正子に届出による日本国籍の取得を認めることはできない。

４ 以上のとおりであって，本件において憲法１４条１項に違反することとなるのは，国籍法３条１項の規定自体ではなく，非準正子に届出により国籍を付与する [P41] という法が存在しないという立法不作為の状態であり，このことから，届出により国籍を取得するという法的地位が上告人に発生しないことは明らかであるから，上告人の請求を棄却した原判決は相当であり，本件上告は棄却すべきものと考える。

なお，藤田裁判官は，非準正子に対し届出による国籍付与をしないという立法不作為が違憲であるとしており，この点で私たちと同一の立場に立つものである。しかし，さらに，国籍法３条１項の拡張解釈により権利付与を認めるべきであるとして，上告人の請求を認容すべきものとしており，この見解は，傾聴に値すると考えるが，同項についてそのような解釈を採ることには直ちに賛成することはできない。

５ 多数意見は，「本件区別により不合理な差別的取扱いを受けている者の救済を図り，本件区別による違憲状態を是正する必要がある」との前提に立っており，このような前提に立つのであれば，多数意見のような結論とならざるを得ないであろう。しかし，このような前提に立つこと自体が相当ではない。なぜなら，司法の使命は，中立の立場から客観的に法を解釈し適用することであり，本件における司法判断は，「本件区別により不合理な差別的取扱を受けている者の救済を図り，本件区別による違憲の状態を是正することが国籍法３条１項の解釈・適用により可能か」との観点から行うべきものであるからである。

６ 日本国民たる要件は，法律により創設的・授権的に定められるものである。

本件で問題となっている非準正子の届出による国籍取得については立法不存在の状態にあるから，これが違憲状態にあるとして，それを是正するためには，法の解釈・適用により行うことが可能でなければ，国会の立法措置により行うことが憲法の原則である（憲法１０条，４１条，９９条）。また，立法上複数の合理的な選択肢 [P42] がある場合，そのどれを選択するかは，国会の権限と責任において決められるべきであるが，本件においては，非準正子の届出による国籍取得の要件について，多数意見のような解釈により示された要件以外に「他の立法上の合理的な選択肢の存在の可能性」があるのであるから，その意味においても違憲状態の解消は国会にゆだねるべきであると考える。

７ そうすると，多数意見は，国籍法３条１項の規定自体が違憲であるとの同法の性質に反した法解釈に基づき，相当性を欠く前提を立てた上，上告人の請求を認容するものであり，結局，法律にない新たな国籍取得の要件を創設するものであって，実質的に司法による立法に等しいといわざるを得ず，賛成することはできない。

The dissenting opinion by Justice KAINAKA Tatsuo and Justice HORIGOME Yukio is as follows.

We consider that the final appeal should be dismissed, for the following reasons.

1. The Nationality Act is a law that creates and grants rights, and it stipulates, in accordance with the provision of Article 10 of the Constitution, what requirements should be satisfied when granting Japanese nationality. Without the provisions of the Nationality Act, the definition of Japanese citizens cannot be determined. Where a person does not satisfy the requirements prescribed in the Nationality Act for acquiring Japanese nationality, it is only as if nothing has been decided in relation to acquisition of Japanese nationality. In other words, where a person fails to conform to the provisions under which Japanese nationality shall be granted, it is nothing more than the state of non-existence of legislation or inaction on legislation in relation to the provisions of the Nationality Act. This also applies to other administrative laws under which the Diet shall grant certain rights or interests to the public from a policy perspective.

2. In accordance with Article 2, item 1 of the Nationality Act, a child acknowledged by a Japanese father before birth shall acquire Japanese nationality by birth. Article 3, para. 1 of said Act also provides that legitimated children born to Japanese fathers may acquire Japanese nationality by making a notification. However, with regard to children who were acknowledged after birth but not legitimated (non-legitimated children), said Act does not contain any provision to the effect that such children shall be granted Japanese nationality upon notification. Therefore, we should say that in relation to acquisition of nationality by non-legitimated children by making a notification, the current situation is nothing other than the state of non-existence of legislation or inaction on legislation.

3. The Nationality Act causes a distinction between legitimated children and non-legitimated children by granting nationality to the former through the notification procedure while closing the door for the latter to acquire nationality through said procedure due to the non-existence of legislation or inaction on legislation (this distinction shall hereinafter be referred to as the "Distinction"). At the time when Article 3, para. 1 of the Nationality Act was enacted, the Distinction had a reasonable basis and was not in violation of Article 14, para. 1 of the Constitution. However, we consider that at the time when the appellant submitted a notification for acquisition of Japanese nationality to the Minister of Justice, at the latest, the Distinction amounted to discrimination without reasonable grounds and constituted violation of Article 14, para. 1 of the Constitution. The reason for this view is the same as the holdings of the majority opinion in 4 above. However, what is unconstitutional is the state of inaction on legislation, or the lack of a provision to grant nationality to non-legitimated children upon notification. While the majority opinion states that what is unconstitutional is the provision of Article 3, para. 1 of the Nationality Act per se, we consider that said provision is not unconstitutional at all because it is a provision that is intended to create and grant a right, i.e. grant nationality to legitimated children upon notification. The majority opinion can be construed to hold that the provision of said paragraph contains a part that means that non-legitimated children shall not be granted Japanese nationality even if they make a notification and such part is unconstitutional and therefore void. However, since such construction goes contrary to the nature of the Nationality Act as a law that creates and grants rights, it is, after all, the same as reading legitimated children as children acknowledged after birth, and it should inevitably be deemed to be beyond the limit of legal construction.

We agree with the idea that where a special provision or a provision that restricts rights is unconstitutional, it is permissible, as a method of legal construction, to make such part of the provision void and apply a general provision in order to grant rights. However, it is obvious that this law case is not such a case. Since the Nationality Act can be deemed to adopt the principle of jus sanguinis, as mentioned in the majority opinion, but cannot be construed to stipulate thorough implementation of the principle of jus sanguinis, the provision of Article 3, para. 1 of said Act cannot be construed to generally grant Japanese nationality to children acknowledged after birth upon notification, while restricting non-legitimated children from acquiring Japanese nationality through the notification procedure.

Consequently, acquisition of Japanese nationality by non-legitimated children by making a notification cannot be allowed according to the construction of the provision of Article 3, para. 1 of the Nationality Act.

4. As explained above, what constitutes violation of Article 14, para. 1 of the Constitution in this case is not the provision of Article 3, para. 1 of the Nationality Act per se but the state of inaction on legislation or the lack of a law that grants nationality to non-legitimated children upon notification, and it is obvious that this fact does not make the appellant legally entitled to acquire nationality by making a notification. Therefore, we believe that the judgment of prior instance that dismissed the appellant's claim is justifiable and the final appeal should be dismissed.

Justice FUJITA Tokiyasu holds that what is unconstitutional is the inaction on legislation which results in not granting nationality to non-legitimated children even if they make a notification, and in this respect, he holds the same viewpoint as ours. However, Justice FUJITA further argues that nationality should be granted to non-legitimated children by putting a broad construction to the provision of Article 3, para. 1 of the Nationality Act and concludes that the appellant's claim should be upheld. We find his view to be worth listening to, but cannot immediately agree to construe the provision of said paragraph in that way.

5. The majority opinion is based on the assumption that "it is necessary to give relief to people who are subject to unreasonable discriminatory treatment due to the Distinction, thereby correcting the unconstitutional condition arising from the Distinction." Such assumption will inevitably lead to the conclusion drawn by the majority opinion. However, it is inappropriate to depend on such assumption, because the mission entrusted to the judiciary is to construe and apply law objectively on neutral ground, and in this case, the court should make its decision from the perspective of "whether or not it is possible, through construction and application of the provision of Article 3, para. 1 of the Nationality Act, to give relief to people who are subject to unreasonable discriminatory treatment due to the Distinction, thereby correcting the unconstitutional condition arising from the Distinction."

6. The conditions for being a Japanese citizen are determined by law through creation and grant of rights. Since the state of inaction on legislation can be found with regard to the point at issue in this law case---acquisition of nationality by non-legitimated children by making a notification, if such state is found to be an unconstitutional condition but it cannot be corrected through construction and application of law, it is a principle under the Constitution to correct this state through a legislative measure taken by the Diet (Article 10, Article 41, and Article 99 of the Constitution). Furthermore, if there are several reasonable options for legislation, the Diet has the authority and responsibility to decide which one of them should be chosen. In this law case, when determining requirements to be satisfied for acquisition of nationality by non-legitimated children by making a notification, there exists "the possibility that there is any other reasonable option for legislation" in addition to the requirement based on the construction given by the majority opinion. Also in this respect, we consider that it should be left to the Diet to decide how to eliminate the unconstitutional condition.

7. For the reasons stated above, we should say that the majority opinion has established an inappropriate assumption according to the legal construction that is contrary to the nature of the Nationality Act, i.e. the provision of Article 3, para. 1 of said Act per se is in violation of the Constitution, and upheld the appellant's claim based on such assumption. The majority opinion, after all, creates a new requirement for acquisition of nationality that is not stipulated by law and it is in effect equal to legislation by the judiciary. Therefore, we cannot agree with the majority opinion.

裁判長裁判官
          島田 仁郎
  裁判官  横尾 和子
  裁判官  藤田 宙靖
  裁判官  甲斐 中辰夫
  裁判官  泉   徳治
  裁判官  才口 千晴
  裁判官  津野 修
  裁判官  今井 功
  裁判官  中川 了滋
  裁判官  堀籠 幸男
  裁判官  古田 佑紀
  裁判官  那須 弘平
  裁判官  涌井 紀夫
  裁判官  田原 睦夫
  裁判官  近藤 崇晴