Six couples have filed a complaint against the Japanese government to demand the right for spouses to have different surnames. Japanese civil law, dating from the 19th century, stipulates that spouses must have the same surname.

In 95% of cases, it is that of the husband who prevails, according to the plaintiffs' lawyers. Defenders of the status quo argue that changing the law would weaken family ties and represent a violation of “traditional values” The plaintiffs are demanding 500,000 yen ($3,400) in compensation per person for the damage suffered.