After the Supreme Court ruled on June 4 that 10 children born to Filipino women had the right to be granted Japanese nationality, every media outlet in the country called the verdict “epoch-making” because the court declared a provision of the Nationality Law unconstitutional.

The fathers of the 10 plaintiffs, all of whom live in Japan, are Japanese men who acknowledged their paternity but are not married to the mothers. The Nationality Law says that a child born to a non-Japanese mother and a Japanese father who aren’t married to each other can only be granted Japanese nationality if the father acknowledges paternity before the child’s birth. The Supreme Court ruled that this provision violates Article 14 of the Constitution, which guarantees equality under the law, since the Nationality Law also states that an out-of-wedlock child who is acknowledged by the father after birth can be granted Japanese nationality if the father and the mother subsequently marry. That means the only difference with regard to granting nationality is the married status of the parents. Such a condition constitutes unequal treatment.

An article in last week’s Shukan Asahi predicted 100,000 new Japanese nationals as a result of the verdict. Many of these potential Japanese already live in Japan, but as many, if not more, reside overseas. Tokyo Shimbun reported that “tens of thousands” of children fathered by Japanese men live in the Philippines alone, and if these fathers officially acknowledge their paternity, the children could legally move to Japan along with their mothers and other close relations.

However, the ruling also has legal ramifications for some children who are already Japanese. A longer analysis of the case that appeared in the Mainichi Shimbun pointed out that even after they gain Japanese nationality, the 10 plaintiffs will still be considered “out-of- wedlock children” and therefore will be subject to discrimination just like other Japanese children whose illegitimacy is indicated in their family registers.

The discrimination mostly has to do with inheritance. The Civil Code states that an illegitimate child of a head of household is entitled to only half the inheritance of a legitimate child. For years the United Nations Human Rights Commission has been pressuring Japan to change this law and otherwise stop distinguishing between legitimate and illegitimate children. A Waseda University professor told the Mainichi that he believes the Supreme Court’s verdict will finally lead to a frank discussion about illegitimacy and a change in the law with regard to inheritance. If the Nationality Law is unconstitutional because it discriminates between children of married couples and children of unmarried couples, then wouldn’t that mean the inheritance provision is also unconstitutional? As long ago as 1996, an advisory panel set up by the Justice Ministry recommended that the inheritance distinction be scrapped, but no relevant bill has ever made it to the discussion stage in the Diet.

Maybe that’s because the nature of the problem is more bureaucratic than legal owing to the structure of the family register, in which offspring are described in terms of succession — first son, second son, first daughter, etc. Children born out of wedlock are simply listed as male or female, thus indicating their illegitimacy. Even if the inheritance provision is changed, illegitimacy would still be apparent in the family register. In 2004 the Justice Ministry began allowing local governments to indicate out-of-wedlock children with terms of succession, thus blurring the difference between them and their “legitimate” counterparts, but it doesn’t erase the distinction, which is obvious to anyone who knows how to read the document.

Illegitimacy is even more of a problem in the case of a 27-year-old woman from Hyogo Prefecture who gave birth to a boy on May 29. Until last week the baby was technically illegitimate even though the woman and the father of the baby held a wedding ceremony last year. But the couple was not considered legally married because the wife does not have a family register. When she was born, her mother had recently divorced. According to the Family Registry Law, any child born to a woman less than 300 days after her divorce is considered to be the child of the previous husband, and the daughter’s birth occurred before the 300-day mark. But the ex-husband was not the real father, and so the mother didn’t register her daughter. In Japan, if you don’t have a family register, for all intents and purposes you don’t exist. The 300-day law has been a topic of contention for years, but despite plans to scrap it, it still stands.

However, last Wednesday, the pertinent local government office made an exception in the new baby’s case and registered his name in the father’s family register after accepting a marriage report from the couple. It was the first time ever that a child born to a mother without a family register was allowed to be entered in the father’s.

There are many other Japanese who for one reason or another do not have family registers, which means they cannot legally marry, obtain passports or vote. In most cases they cannot receive public services, such as free education, but because these cases are “exceptional,” solutions such as the one in Hyogo have to be makeshift. It’s pretty much up to the local government. The bureaucracy and the ruling coalition don’t want to change the family-register system, and since the annual number of out-of-wedlock births to Japanese mothers has doubled in the last decade, the issue of whether or not illegitimate children receive equal treatment under the law will likely become even more complicated.