One of the features, or, depending on your perspective, problems of the koseki (Japan’s family registration system) is that it embeds deeply into the legal system a very basic distinction between koseki insider and outsider — those registered in it and those who are not. It thus legitimizes — mandates — certain types of discriminatory treatment.

First, members of Japan’s Imperial family are all outsiders, tracked through a different registry known as the kōtōfu. When a princesses marries out of the Imperial family (as they must, there not being any marriageable princes), she becomes a “commoner,” a process accomplished by entering her into the koseki system and noting her exit from the rank of royalty in the kōtōfu.

At the other end of the spectrum, there is also a small but significant number of mukosekisha, people who for various reasons never had their birth registered in a koseki. They can have a tenuous legal existence because of their inability to furnish a basic Official Document to prove their birth, identity, marital status and so forth — all of which usually can be verified using a koseki extract.

Finally, the most numerous koseki outsiders are Japan’s foreign and ethnic Korean population. This is because the entire system is linked to nationality in a chicken/egg-like fashion: You are a Japanese national because you are registered in a koseki, which you are registered in because you are Japanese. Having a koseki is proof of Japanese nationality, and naturalizing as a Japanese citizen means establishing a koseki registration.

Non-Japanese family members appear as marginal notations — parents, spouses — in a Japanese person’s koseki but they are otherwise dead ends that cannot be traced further in genealogy of the koseki. Until recently foreigners were tracked through the Alien Registration system, but they now get their Official Documents mainly from the residence registry, as is increasingly the case with Japanese people as well.

The prewar koseki system was even more nationalistic in rendering nationality a family affair: Everyone in a koseki had to be Japanese. Marrying a foreigner meant the foreign spouse joining the koseki and becoming Japanese or the Japanese spouse leaving the koseki and losing their Japanese nationality.

The first national koseki system adopted in 1872 simply treated everyone who clearly hadn’t just alighted from a Black Ship as Japanese. Complications arose once Japan acquired colonies (Taiwan and Korea) with very different systems of family law that necessitated different koseki systems. Marriages or adoptions across territories meant moving from one system to another. These multiple koseki systems became part of a system that differentiated between nationality, an international law concept, and citizenship, a domestic one. A Korean might be a Japanese subject abroad, but within the empire, the koseki they were registered in limited their freedom to travel to the Japanese islands and was the basis for denying them political rights.

When Japan lost its colonies after World War II, the question of who remained Japanese and who didn’t was based on koseki registrations. Those in a Japanese koseki remained “Japanese,” those in a Korean or Taiwanese koseki become something else, even if they were living in Japan when the war ended. For those of Korean heritage (or who married into Korean families), this initially meant something close to statelessness because of the turmoil, partition and war on the Korean Peninsula. By contrast, those registered in a Taiwanese koseki could at least become citizens of the Republic of China and enjoy the extraterritorial status accorded to nationals of the victorious Allied powers until the end of the Occupation.

Everyone watching everyone else

Some may wonder why Japan needed a koseki in the first place. Well, after the Meiji Restoration of 1868, the government of Meiji Japan had to unify a fractious patchwork of feudal domains into a single nation while building the economic and military infrastructure to ward off colonial western powers. It needed tax revenues and conscripts.

But to implement any meaningful policies, it needed basic demographic information about the Japanese people. And where they were — the Meiji Restoration was a time of great social disruption, with rootless, unidentified people roaming the lands. The forerunner to the modern koseki system was first introduced in Kyoto, once a center of intrigue and a magnet for political schemers and other people of questionable motivation.

The national koseki system thus started as part-demographic information collection system, part-surveillance apparatus. Unlike today, the system originally was more closely related to residence and complemented by a separate registry system for anyone spending more than 90 days away from the location of their koseki, a system retained until 1952, when the current system of residence registration was introduced.

Under the prewar system, larger extended families of three or four generations would all be registered as a single ie or household. The prewar Civil Code also required each family to have a koshu (head of household), a heritable status that came with various responsibilities and rights, including the authority to dispose of family property. Koshu status was registered in the koseki, so that the Rest of The World could know who he was. For members of the aristocracy that existed in prewar Japan, the koseki showed the heir apparent to the family title.

In the past, the koseki system gave the government leverage; policy could be directed at the family rather than the individual, with heads of household responsible for implementation. In exchange, families and their heads were accorded broad autonomy to regulate themselves. This autonomy meant that “The law shouldn’t intrude into the family” became an enduring notion in Japan, one that only recently shows signs of falling to the wayside, possibly because families themselves are losing importance as a legal component of society.

The postwar American occupiers regarded the ie system as a part of the structure of Japan’s fascist state that needed to be changed. Their stamp on Japanese family law can be seen in gender equality and the elimination of the koshu status. They also proposed replacing the koseki with a system of individual registration but met with resistance from their Japanese counterparts. The Japanese prevailed and the system survived, but the Americans demanded that it be impossible to register more than two generations in a single koseki. The current koseki system is thus a vestigial remnant of a much more intrusive government apparatus, the byproduct of an odd compromise over an artifact of legal history, one that retains the family as the central unit of society (despite a Constitution mandating respect for the individual!) but strictly restricts the scope and extent by which the family can be legally defined.

Apart from government, in the past the koseki once offered a means of evaluating the creditworthiness and reliability of an extended family in commercial dealings, marriage and other social interactions. The koseki made every Japanese family an open book — quite literally. Until access restrictions were introduced in 1976, anyone could pay the statutory fee and peruse another person’s koseki. Not only that, but in the past, far more information was recorded in the registry. Unusual deaths, different categories of children born out of wedlock, and even criminal records were recorded in prior versions of the koseki. (Now criminal records are maintained in a separate registry.) The koseki was thus part of a panopticon-like system in which everyone would feel that they were being monitored but could also participate in the monitoring process. The current Japanese preoccupation with privacy may thus reflect recent historical experience of not actually having any.

The cost of not keeping up to date

For the koseki to work, of course, people have to register in it. Since its introduction this has been accomplished by tying registration to various benefits, including, at the most basic level, the protection of the state accorded to Japanese nationality.

Here the registration requirement remains harsh: A child born abroad to Japanese parents who is not registered in the koseki within three months becomes ineligible for Japanese nationality. It should also be remembered that as written, Japan’s Constitution only accords rights to Japanese nationals (though interpretively it is more complex).

Another incentive to registration was inheritance; the Civil Code of 1898 was drafted so marriages were only legal if registered (as is still the case). Children born to an unregistered union would be illegitimate and disadvantaged in their ability to inherit family property or hereditary titles. Legitimacy-based discrimination in inheritance rights remained on the books until 2013, when the Supreme Court finally declared them unconstitutional.

Much of what casual observers may associate with “Japanese tradition” in the area of family law may actually have been imposed on the country through the uniform registration requirements of the koseki system. It rendered largely moot a rich and regionally diverse variety of matrimonial customs and practices (including, according to one frustratingly sparse sentence in a book on the koseki, some contractual same-sex marriages) that existed in various parts of Japan before the Meiji Period.

The registration requirement encouraged the practice of not registering a marriage until a child was conceived; this presumably saved families the bother of divorcing a barren wife and dirtying the koseki with a record of an unproductive union. This practice persisted well into the postwar period. In 1966 an ANA flight crashed at Matsuyama airport killing everyone aboard, including 12 couples partaking in the newly fashionable practice of taking a honeymoon after their wedding. It transpired that not one of these marriages had been registered, making negotiations between the airline and surviving family members complicated because legally the “husbands and wives” were still unrelated strangers. In response, the Justice Ministry introduced a PR campaign encouraging newlyweds to register their marriages.

The koseki system is showing its age. As a source of identification it is declining in importance. Third-party access to koseki records is now tightly restricted, and companies are not supposed to ask for koseki records from prospective employees. I have even heard rumors — rumors! — of a Ministry of Justice team tasked with planning the abolition of the koseki system in its entirety. While the recently introduced My Number system of personal identification has generally been described in terms of its importance in the tax and social insurance system, the Justice Ministry recently published a report on all the ways in which My Number could serve as a source of Official Documents in lieu of koseki extracts.

Perhaps this will serve as an opportunity to get rid of the archaic family rules entrenched in the koseki that cause many Japanese people — women and children in particular — pointless suffering and inconvenience. Of course, the presence of those rules may also be precisely why conservative political forces might oppose any effort to let the koseki die of old age.

This is the last of a two-part series on the koseki system. Part 1 is here. Colin P.A. Jones is a professor at Doshisha Law School in Kyoto. The views expressed are those of the author alone. Law of the Land usually appears on the second Monday Community Page of the month. Comments and ideas: community@japantimes.co.jp

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