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.