Nationality as state affiliation
By William Wetherall
Nationality, though often confused with citizenship, and with race or ethnicity, is none of these. Nationality is a legal status that makes one an affiliate of a state's sovereign nation regardless of one's race or ethnicity, and regardless of what elements of citizenship may derive from nationality.
Nationality is what affiliates a person with a state's demographic territory or nation. People who possess a state's nationality are nationals of the state. All others are non-nationals or aliens. However, all residents of a country -- nationals and aliens alike -- are to some extent its "citizens" broadly defined as the members of its society, though the quality of their membership -- their "citizenship" defined as a set of rights and duties -- may individually vary according to a number of personal factors.
Many factors, in addition to nationality, determine the quality of a person's rights and duties as a resident of a country -- or even as a sojourner or illegal alien. Other factors include sex, age, legal competency other than because of age, such as mental condition or criminal record, family status or "status relationship" as a child, parent, spouse, or other blood or in-law relative, and of course place and status of residence, possibly tax status, and so forth. The significance of such factors varies with country and region within a country.
As sovereign entities, states are free to determine the qualifications for acquiring and losing their nationality. The nationality laws of all states utilize both right-of-blood (lineage) and place-of-birth (locality) principles to determine nationality at time of birth. Nationality laws also make provisions for naturalization, denaturalization, and renouncement.
Some people are nationals of two or more states, some of no state. All people are viewed as aliens by states other than those of their nationalities. Stateless people are aliens everywhere. No state embraces multiple nationality as a principle, but most tolerate its natural occurrence (at time of birth). In practice, most states -- including those that accept multiple nationality -- recognize only one nationality at a time.
All states treat nationals and aliens somewhat differently under their laws. This is inevitable given the reasons states exist in the first place, as governments responsible for protecting the interests of their nationals.
All states also treat nationals from other states differently according to their relations with the other states. Nationals of one state may be able to enter and reside in a certain country with few restrictions, while the entry and sojourn of those from another state may be strictly controlled.
States are increasing bound by international treaties to guarantee basic human rights to their nationals but also to aliens. However, as sovereign entities, states remain fairly free to reserve elements of citizenship like rights of residence and suffrage for nationals.
All of the above statements apply to Japanese nationality and Japan's Nationality Law. Since the legal birth of Japan's nationality in the 19th century, Japan's nationality laws have been very typical among the nationality laws of the world's many states.
Nationality primer
Nationality primer provides a quick overview of nationality in Japan with annotated links to all related articles on this website.
Elements of citizenship
Elements of citizenship: Social and political belonging in Japan is divided into two parts. Status and citizenship examines the relationship between state and local affiliation in Japan and the rights and duties that come with such legal statuses, for Japanese and aliens. Aliens and the Constitution second looks at how the 1947 constitution came to differentiate between "kokumin" (nationals, "the people") and "nanbito mo" (anyone, "every person"), and at how some court cases have tested the letter and intent of this distinction with regard to the rights and duties of aliens affiliated with Japan.
Family registration
Household or family registration and related laws, presented first because family registers in jurisdictions of polities in Japan's sovereign dominion essentially define who is Japanese by virtue of possessing Japan's nationality.
The collective imperatives of the human condition are seen in all manner of groupings, from couples and families, to villages, nations, and even multinational coalitions. While concerned with different groups, parents and sovereigns share the need to know how many heads they need to feed or tax.
Demographic records of various kinds have existed for as long as there have been systems of writing. According to Japan's earliest chronology, registers were kept from no later than the middle of the 6th century for at least some households, including those of Hata, Aya, and other migrants from the peninsula who who were settled in various Yamato provinces.
Household registration for the purpose of allocating land for cultivation and levying taxes became more systematic by the middle of the 7th century. And by the start of the 8th century, such record keeping had become a matter of statute law.
Over the next several centuries, registers evolved into more comprehensive records of vital events, including birth, death, marriage, and divorce, maintained by household. From the 17th century, such records came to be kept at local temples, partly to ascertain that no family had become Christian.
The present Family Registration Law dates from 1872, when household registration was consolidated under secular local governments nationwide. Since register matters followed customary family law, such family law as was codified in the Civil Code was essentially defined by standardized family registration practices.
Japanese household or family registers (戸籍 koseki) are essentially national registers (国籍 kokuseki) in that they define the membership of Japan's "nation" (国民 kokumin). Note that the term "kokumin" (国民) is used to refer to both an individual "national" and the collective of "nationals" defined as people who possess Japan's "nationality" or "kokuseki" (国籍).
Japanese nationality is essentially territorial. Becoming Japanese through birth is based on family lineage (right-of-blood) or, in some cases, by birth in Japan (right of soil). And there are provisions for acquiring Japanese nationality later in life regardless of lineage or place of birth. But as a civil status, Japanese nationality is territorial.
Being a national of Japan means that one is part of its demographic territory -- its nation, its people. But the nationality one possesses is linked with Japan's geographic territory.
Proof that one possesses Japanese nationality, and is therefore a national of Japan, is recognition by the state that one possesses, or by law has a right to possess, a "principle domicile register" -- a "honseki" (本籍) -- in the form of a "household register" or "family register" or "koseki" (戸籍) -- the address of which is in a polity within Japan's sovereign dominion. Nationality -- in other words -- is directly tied to affiliation with a piece of territory within a local government entity -- a municipality -- of Japan. That's what it comes down to in essence.
Japan did not legally define itself as a nation until 1868, when a new government set out to nationalize what it considered the emperor's inherent domain. As an imperial nation, Japan was obliged to define its nationality and establish legal criteria for the gain and loss of its nationality, while considering the nationality laws of other countries.
Until the first Nationality Law in 1899, the equivalent of nationality in Japan was determined by customary family law, and by statutes that facilitated change of status in family registers under the Family Register Law of 1872 and later revisions. Consequently, the Nationality Law itself is based on conventions of family law, which generally comport with the nationality practices in most other countries.
Nationality laws
Here you will find information about Japan's nationality laws. The nationality laws of a few other countries are grouped under "Nationality in other states".
I became interested in Japan's Nationality Law for personal reasons. Though I now possess Japanese nationality, at the time I first came to Japan I possessed only US nationality. I was married to a Japanese national, and my children, born in Japan, were not recognized as Japanese because Japan's Nationality Law at the time -- 1978 when my daughter was born, and 1982 when my son was born -- was patrilineal in the case of a Japanese woman married to alien.
I thought the patrilineal constraint violated Japan's Constitution, which eulogized the equality of the sexes under law, and so I and my wife sued the Japanese government for recognition of our children as Japanese. My as children were born overseas, and because I had lived in the United States for 10 years, 5 of those after turning 14, the US consulate in Tokyo recognized that they qualified as US citizens by right of blood.
Nationality in Japan
"Nationality in Japan" (2006) is a general overview of the development of Japanese nationality from antiquity to the present. The article -- first published in 2006 but constantly updated on this website -- shows that Japanese nationality has always been a purely legal status having nothing to do with race or ethnicity, and that it has been based on international standards since the first Nationality Law in 1899.
The article describes how the 1899 law came to be degenderized, partly in 1950 and more fully in 1985. It also looks at current issues that remain to be addressed in future revisions.
Minor revisions came into effect from January 1994 and 2005. More important revisions came into effect from 2009. These revisions are presented in the "2009 Nationality revisions" article.
Nationality laws and translations
The articles on Japan's nationality laws contain Japanese texts and English translations. The translations of the older laws are mine. The translations of more recent laws are shown as published but with corrections and annotations. Keep in mind that no English translation is recognized under Japanese law.
Nationality lawsuits
There have been many nationality confirmation lawsuits in Japan. Several have reached the Supreme Court, the judgments are important as legal interpretations of how Japan's Nationality Law, in conjunction the Civil Code and Family Register Law, operates in the determining who qualifies for Japanese nationality.
Shapiro v. State (1977-1982)
Sugiyama v. State (1978-1988)
Two court cases with similar aims, and litigated by the same team of attorneys, challenged the constitutionality of the Nationality Law in the years leading up to its revision in 1984, effective 1985. I have reviewed both cases here, but have given more attention to Sugiyama v. State, because it got more media attention and was appealed to the Supreme Court -- and I happen to have been a parent-guardian co-litigant with daughter and son, who were plaintiffs, and their mother, who was both a plaintiff and a parent-guardian co-plaintiff.
In the case of children born to married Japanese, the Nationality Law was patrilineal. The children in the Shapiro and Sugiyama cases were considered ineligible for Japanese nationality, because their mothers were married to alien fathers who were not stateless. The law was matrilineal for a child born to a Japanese woman out of wedlock, or born to a Japanese woman married to a stateless man. The child plaintiffs in both cases sought to confirm that they should be Japanese because the patrilineal criterion discriminated against their mother on account of her sex, and consequently against them, and was therefore unconstitutional.
Revisions made in 1984, effective from 1985, enabled our children, and many like them, to become Japanese upon notification under special transitory measures in the Supplementary Provisions of the revised law. They became Japanese in 1987, and because the revision had removed the causes for their lawsuits, by then in the Supreme Court (daughter) and Tokyo High Court (son), we withdrew both appeals in 1988, thus ending a decade of litigation.
Nationality in legacy law
Occupied Japan 1945-1952
Post-Occupation 1952-20xx
"Legacy law" as I use the term is the application of the provisions of abrogated laws, or of older provisions of current laws, in determining present status. Unless the effects of older laws, including treaties, are nullified retroactive to the day of enforcement, by the state in which the provisions of the law or treaty operated, the effects of the provisions continue to have legal validity.
Accordingly, in Japanese courts, (1) the Empire of Korea did the Japanese territory of Chōsen in 1910 as an effect of the union of the Empire of Korea with the Empire of Japan, (2) Koreans did become Chosenese on account of their being members of Chōsen household registers, and (3) Chosenese did become Japanese on account of Chōsen becoming part of Japan's sovereign dominion, and (4) Chosenese did lose their Japanese nationality in 1952 on account of Japan abandoning its claim to Korea (Chōsen) under the terms of the San Francisco Peace Treaty, and (5) throughout the period that Chōsen was part of Japan, Chosenese were subject to a variety of laws and ordinances, some of them specific to Chōsen, others specific to the prefectural Interior, others applicable throughout the Empire of Japan.
In other words, the "past" continues to live in courts that deal with private matters -- nationality, marriage and divorce, alliances of adoption, parental (paternal or maternal) acknowledgement, inheritance and other property issues -- that span the past and present.
All of the articles and court cases in this section dramatize the complexities of nationality changes following wars or other conflicts that result in territorial transfers. Redrawing a national boundary typically engenders nationality changes, whether mandatory or optional, of inhabitants of the affected territories.
Nationality settlements are generally made in treaties, but in the case of separating Chōsen from Japan, they were left to the discretion of the concerned states -- Japan, ROK, and DPRK. In their 1951-1952 talks, which were supposed to result in normalization of their relationship in 1952, Japan and ROK reached an agreement over the nationality status and treatment of Koreans (Chosenese) in Japan.
The agreement was never signed, though, because the talks were scuttled by disagreement over other issues. Nevertheless, the spirit of the draft of the status agreement resulted in Japan regarding Chosenese in Japan as having lost their Japanese nationality but gaining a tentative permanent residence status. These effects have been recognized by Japanese courts.
In the meantime, the status agreement signed by ROK and Japan in 1965, when they finally normalized their relationship, confirmed that aliens in Japan of ROK nationality, who qualified under the terms of agreement, would acquire a special permanent residence status. The loss of Japanese nationality in 1952 was never an issue in the eyes of ROK, which (1) regarded the annexation of Korea as illegal, hence Koreans never legally become Japanese, and (2) recognized that Japan had the right to determine who it admitted to its nationality.
Japanese courts have based their rulings in legacy nationality confirmation cases only on civil status as determined by applicable laws at any given point in time -- not on putative ethnicity, which is not codified -- and is therefore essentially irrelevant -- in Japanese law.
Nationality in other states
While studying Japan's Nationality Law, I began to examine the nationality laws of other countries also. The laws of Japan's closest neighbors -- China and Korea, now two Chinas and two Koreas -- have been the most important for Japan, simply because the Japan's demographic relationships with these two countries have been more intimate.
The nationality laws of China in the past, and today the Republic of China (ROC) and the People's Republic of China (PRC) -- and Korea in the past, and today the Republic of Korea (ROK) and the Democratic People's Republic of Korea (DPRK) -- have determined their nationality essentially as Japan has, primarily through jus sanguinis and secondarily through jus soli criteria. China and Korea, like Japan in the past, preferred patrilineal jus sanguinis, as did ROC and ROK when they were founded. DPRK and PRC, as socialist states, when establishing their nationality laws, shifted to ambilineal jus sanguinis. Japan, ROK, and ROC adopted ambilineality later.
The laws of countries like United States and Uruguay are of interest mainly in that, as right-of-soil states, their laws differ somewhat from those of right-of-blood states like Japan, China, and Korea. I have also looked at German and French nationality laws, because they shed light on the history and variety of nationality laws in Europe, and because their laws influenced the development of Japan's first Nationality Law in 1899.
Nationality laws vary from country to country, and within countries as laws change with the times. However, the more I looked into the legal convolutions of nationality in Japan and other countries, the more I realized that the standards of Japan's Nationality Law, though not at the time (and not yet) ideal, have always been comparatively high -- and fairly standard.
Nationality in China
In the articles on nationality in China, you will find the original texts and most widely circulated translations of the current nationality laws of both the Republic of China (ROC) and the People's Republic of China (PRC). I have retranslated some parts in order to clarify their meanings. There are also accounts of China's nationality laws under the Ching (Qing) Dynasty.
Nationality in Manchoukuo
A new state usually needs to define who belongs to its nation -- it's affiliated population -- even if this means simply declaring that everyone already living in the state's territory is deemed to possess its nationality. Such "initial determinations" are also usually accompanied by rules for acquiring nationality through birth or later in life, and for renunciation or loss of nationality.
At some point, a new state also needs to enumerate its inhabitants in a census that differentiates them according to place of residence, nationality, sex, age, and occupation, and possibly also education, language, place of birth, religion, race, disabilities, family relationships, and other information the state deems it needs in order to govern. Census data might be compiled by analyzing up-to-date local population registers, or collected by door-to-door canvassing -- or, today, distributing and collecting machine-readable printed questionnaires, or soliciting submission of information through census forms posted on a webpage.
In Manchoukuo, founded in 1932 and restyled an empire in 1934, the enumeration of Manchoukuoans and aliens in the Manchou Empire was facilitated through a "Provisional people's register law", which was promulgated in 1940. The law required local authorities to classify the so-called "five races" that comprised the new nation, but also other inhabitants. The law and its enforcement regulations were drafted with the participation of Japanese legalists in the Manchoukuo government, who wanted Manchoukuo's population registers to differentiate Japanese residents by their subnational (regional and provincial register) statuses under Japanese law.
Nationality in Korea
The Empire of Korea did not have nationality law as such but determined Korean status under customary family laws. The first fully developed people's register law was introduced under Japanese guidance before the Korea was annexed. This law and its revisions, and the family register laws introduced after the annexation, determined Chosenese territorial status during the years that Chōsen was part of Japan.
Japan's 1899 Nationality Law, originally a prefectural Interior Law, was applied to Taiwan and and later to Karafuto, both parts of Japan's sovereign empire, but not to Chōsen. This did not effect the fact that Chosenese were Japanese, since its own population register and family laws continued to determine membership in Chōsen registers, which were part of Japan, hence their members were Japanese. It meant only that there were no provisions for Chosenese to lose their nationality through marriage with an alien, or to renounce their nationality, or for aliens in Chōsen to become Japanese through marriage or naturalization.
ROK and DPRK, established after Korea (Chōsen) was "liberated" from Japanese rule, established their own nationality laws. ROK's law was heavily based on Japan's 1899 law. DPRK's law, like PRC's law, recognized those who possessed its nationality as "citizens" rather than "nationals" -- signifying that they were affiliated with the "public" or "people" rather than with the "nation" or "state".
Nationality in the United States
While nationality laws in Japan and the United States appear to be very different, they are more alike than not. America's nationality or "naturalization" laws, though, have on the whole been more complex.
The United States, since its founding, has differentiated between "nationals" and "citizens". Practically all people who possess U.S. nationality are "citizens" but citizenship is not a universal effect of U.S. nationality.
A U.S. passport bearer is a "citizen/national" of the United States, but under international law, is merely a person who possesses the "nationality" of the United States.
In the first century of American history, race was a factor in the determination of citizenship of people born in the Union states. Until the second half of the 20th century, race also determined who qualified for naturalization.
Only people born in states are constitutional citizens. Those born Washington, D.C. or in a U.S. territory are statute citizens or nationals. Rights of federal suffrage may depend on where one resides in the Untied States. The right to vote in presidential elections was not extended to U.S. citizens residing in Washington, D.C., until the ratification in 1961 of Amendment 23 to the U.S. Constitution. Residents of the District of Columbia first voted in the 1964 election.
The quality of U.S. "citizenship" has considerably varied with the citizen, depending on age, sex, state of residence, and in some states race. Women did not qualify as "citizens" for purposes of suffrage until Amendment 19 of the U.S. Constitution was ratified in 1920.
Race and sex were also once factors in determining whether a child of a white "citizen" and an Indian "national" of the United States was a citizen or national. The child of a white male citizen and female member of a reservation tribe stood to become a citizen.
Blood quantum and civil status were factors in determining property rights. Non-reservation Indians, who paid taxes, were U.S. citizens. Those who remained members of semi-sovereign Indian nations, hence not subject to taxation, did not become citizens until a 1924 act of Congress made them so.
Uruguayan nationality
"Citizenship" is ordinarily considered an attribute of "nationality". However, in Uruguay, citizenship -- defined as rights of suffrage -- may be seen as an independent legal status that does not require nationality.
Nationality in Europe
The main currents in European nationality laws are represented in the European Convention on Nationality, an instrument of the Council of Europe, which has 47 member states as of 2014.
Nationality issues
While nationality is a personal status, its attribution -- at birth or later in life -- has both social and political effects. Some nationality problems are socially and politically more prominent than others.
The articles in this section examine issues that have become important in Japan. Some also make to similar issues in other countries.
Derivative nationality
"Derivative nationality" is nationality acquired as an effect of an international alliance of marriage or adoption, or other such act. Japan's 1899 Nationality Law, like the laws of most states in past, provided that an alien woman who married a Japanese gained Japanese nationality, and that a Japanese woman who married an alien would lose her Japanese nationality if she acquired his through marriage.
Japan's 1950 Nationality Law -- as have the laws of most states -- eliminated all forms of derivative acquisition and passive loss of nationality, out of respect for the notion of individual rights regarding changes of nationality.
While nationality acquired as an affect of being a child of a citizen or national derives from the parent-child relationship, such acquisition is not included in the usual definition of "derivative" nationality. Arguably, nationality attributed on account of having rendered meritorious service to the country, or because of having invested in a country's industry, is a form of nationality "derived" from contributing to the state's "national interest".
Naturalization
"Naturalization" is an overview of allegiance change and naturalization in Japan past and present. Other articles focus on particular periods and several include tables of statistics.
Most people who naturalize are changing their nationality from that of one state to another. The notion that everyone has a "right to change nationality" implies that another nationality is available, and does not imply a right to renounce one's nationality in to become stateless. Most states expect naturalizers to renounce or at least relinquish their other nationalities, but not all states allow their nationals to renounce their nationality.
Names in family registers
"Can Pak be Japanese?" (1983) is an older but still useful review of misunderstandings of name restrictions in family registers, with a focus on so-called "non-Japanese" names.
Naturalization procedures
"How to become Japanese" (1988) compares naturalization in Japan and the United States circa the 1980s. Naturalization in Japan takes a little legwork but has never been difficult. Naturalization in the United States requires, on the whole, about the same amount of personal determination and bureaucratic perseverance.
Dual nationality
"Dual (multiple) nationality" shows that, while Japan does not encourage Japanese adults to also be nationals of other countries, dual nationality is not today, and in fact has never been, illegal in Japan, and the number of dual nationals is increasing.
Statelessness
"Statelessness" looks at why some children have been born stateless in Japan, and why some adults in Japan have become stateless.
"Statelessness treaties" is a collection, with commentary, of international conventions and other measures that seek to eliminate stateless, out of recognition that everyone has a right to a nationality.
"Rees v. State, 1992-1995" examines one of the more interesting and important Supreme Court rulings, which agreed that the child plaintiff should be regarded as having acquired Japanese nationality at time of birth through the jus soli provision in Japan's nationality law, which applies to children born in Japan to unknown or stateless parents. The ruling did not explicitly address the plaintiff's putative "right to a nationality" under United Nations conventions, but kept its argument entirely within the framework of Japan's Nationality Law.
Recognition and legitimation
"Recognition and legitimation" examines the legal wrinkles of nationality acquired through parental (paternal or maternal) acknowledgement, or through the marriage of the recognizing parents.
"Ko v. State, 1993-1997" -- in which the Supreme Court ruled that a child acknowledged after birth acquires nationality through birth -- is one of the most important cases among several regarding recognition.
"Filipinos v. State, 2003-2008" examines the Supreme Court ruling the legitimacy requisite in the 1985 revision to Japan's 1950 Nationality Law was unconstitutional as a condition for attributing nationality.
Adoption and surrogacy
"Adoption and surrogacy" looks at nationality issues related to child adoption, and to surrogate birth and other methods of reproduction that are not yet legally recognized in Japan. Adoption and surrogacy are not necessarily related, but adoption is often the only legal way that a mother of a child born through surrogacy is able to gain legal custody of her child. The issue is more complicated when the child is born through surrogacy outside Japan, and even more complicated when the surrogate child is the product of a donated ovum or sperm.
Nationality and suffrage
How have the twin rights to elect public officials, and to be elected to public office, developed in Japan? Have these rights of suffrage been conditioned on civil status, including nationality?
How did territorial status -- as a member of an Interior, Taiwan, Karafuto, or Chōsen household register -- affect rights of suffrage of subjects of the Empire of Japan? How did rights of suffrage change in Occupied Japan? How have then changed since the Occupation ended?
Nationality and social welfare
In relation to Japan, "social welfare" embraces everything from national health insurance and national pension, to various kinds of allowances for mothers and families, public assistance for disabled and indigent people. Eligibility generally requires possession of legal residency status in Japan, and Japanese nationality has sometimes been a condition.
Since 1982, nationality ceased being a qualification for receipt of a disability pension. However, in "Shiomi v SSA, 1973-1989" the Supreme Court held that nullification of the nationality clause that in the National Pension Law law did not oblige the state to make retroactive measures for benefits for those who did not qualify when the clause was in force. This continues to be the benchmark in court rulings in related cases.
Second-generation nationality
Within the framework of Japan's primarily jus sanguinis Nationality Law, should children born in Japan to aliens have the right to acquire nationality later in life, by operation of the law rather than through naturalization? To what extent should such a right be predicated on their and/or their parents' status of residence and residency history?
Nationality abuse and fraud
In Japan, as in a number of other countries, there is an increase in cases involving alien mothers who wish to acquire nationality for themselves or for a child, or to acquire a status of residency for themselves and/or a child, who abuse the law or resort to fraud, in collusion with Japanese who stand to profit by posing as a husband and/or father.
Bogus marriages are difficult to discover, and immigration authorities don't have the resources to investigate more than a few suspicious marriages. Since the Nationality Law was revised in 2009, to allow acquisition of nationality through parental (paternal or maternal) acknowledgement alone, without legitimation through marriage, fraud becomes easier because there is no need to resort to a bogus marriage. Notifications of acknowledgement, usually by a Japanese father recognizing the child of an alien woman, require supporting documents. Since 2009, the penalties for violations have become stiffer, and are clearly stated on notification forms and in related literature, and presumably officials are more alert for false claims and forgeries.
Nationality after death
Because a person ceases to exist upon death, the person's legal statuses, including nationality, generally cease to exist from that point in time. However, such legal statuses may continue to have effect in laws that stipulate at-time-of-death conditions, as do many jus sanguinis provisions in nationality laws.
Family and alien registers
"Family and alien registers" originally argued why both Japanese and foreign citizens of Japanese municipalities would be better served by a population registration system that merged alien registers into the family registration system that presently includes only Japanese.
This had been my position since the late 1970s and early 1980s, when I personally faced the situation in which there were no provisions to (1) record my marriage or paternity on my Alien Registration Ledger (外国人登録原票 Gaikokujin tōroku genpyō), and (2) record even the birth's of our children on my wife's family register. This was also my position when writing "Nationality in Japan" (2006).
From 9 July 2011, after I had become Japanese, the alien registration system was scrapped in favor of a system for enrolling alien residents on municipal resident ledgers in the same manner that Japanese residents are enrolled, resulting in what is called a "Resident Register" (住民票 Jūminhyō). Co-residing parents and children of different nationalities, including Japanese, can now be represented on the same certificate.
My new complaint is that my family register, while duly recording the my name, date of birth, place of birth, and mother's and father's names and birth dates, and my nationality before becoming Japanese -- no particulars are shown regarding my existence in Japan prior to the date I officially became Japanese. Though my ex-wife's family register shows that she was married to and divorced from me, and that she has two children of whom I am the father, no information appears on my family register to show that I have ever been married, or am the father of two Japanese nationals.
The day I became Japanese, I ceased being an alien. As my place of residence didn't change, the city in which I live created a family register showing a slightly abbreviated form of my residence address as my principle legal domicile. It also created a resident register, and resident ID card, showing me residing at a fuller version of the same address. And, since I was no longer an alien, as required by law it sent my alien registration ledger to the Ministry of Justice for arcivhing.
Before the city divested itself of my alien registration records, I requested -- as was able to by law -- a copy of my alien registration ledger, which showed a full record of all my residences in Japan since my period of continuous residence began in 1975 -- some 35-odd years of existence in Japan, at my present address, at an earlier address in the same city, and at an address in another city, which forwarded my ledger to the city in which I now live when I moved there.
The movement record of Japanese who are born into a family register in Japan is clearly shown in their full register, but naturalizers are "born" into their register as though they didn't exist in Japan before their "birth" as Japanese. Records of their prior existence in Japan are kept in remote and difficult to access archives.
Applicable law
"Nationality" is an attribute of domestic law, which means that each state defines the parameters of its own nationality. Every state also differs in how it enforces its laws in private matters, such as marriage and divorce, inheritance, and property matters. In private matters involving venues in more than one country, and/or people of different nationalities, conflicts arise as to which country's laws should apply to the matter.
International private law involves "laws of laws" -- or rules for determining such things as which country's laws apply in a certain case, and which country's courts have a right to hear the case and issue a ruling. One's nationality -- as well as one's domicile and/or habitual residence -- will determine whether one's "home country law" ("national law") (本国法 hongokuhō) applies in a given private matter, or whether the laws of the country in which one resides, if not of another country, apply.
Subnationality settlements
A state's overarching nationality may include several "subnationalities" that represent affiliations with territories that are governed under different legal systems that require laws of laws to determine applicable territorial law in private matters. The different states and territories of the Federal United States represent such territories, as do the reservations of recognized Native American nations.
The Empire of Japan had several such distinct jurisdictions, including the prefectural Interior, Taiwan, Karafuto, and Chōsen within its sovereign dominion, and within its larger legal dominion the Kwantung Leased Territory in Manchuria and South Sea Islands.
"Subnationality settlements" looks at the legality of Japan's treatment after World War II of subjects of its lost territories, particularly of Taiwan and Korea, who were in the Interior when Japan formally surrendered and remained in Occupied Japan.