The Diet passed a bill Thursday to remove a discriminatory Civil Code article against the inheritance rights of children born out of wedlock.
The Upper House passed the bill shortly after midnight Wednesday in a unanimous vote. The Lower House passed the bill late last month.
The change scraps Article 900, which capped the inheritance that an out-of-wedlock child could receive at half that of a legitimate child.
The government introduced the bill after the Supreme Court said in a landmark ruling in September that the Civil Code clause was unconstitutional. The Supreme Court also said it should not be permitted that someone should be at a disadvantage merely for having unmarried parents, a matter in which the child has no choice.
The court said it took into account changes in attitudes toward family arrangements and a global trend to eliminate discrimination.
Some conservative members of the ruling Liberal Democratic Party voiced opposition to the change, saying it would “destroy the traditional family system.”
Also put to a vote at the Upper House plenary session was a bill to scrap a family registration law provision that requires parents to specify whether their newborn babies are legitimate children or not when registering their births.
The bill, cosponsored by four opposition parties, was rejected as the LDP and Nippon Ishin no Kai (Japan Restoration Party) voted against it. The LDP’s coalition partner, New Komeito, supported the change.
The ruling bloc had initially planned to introduce a similar bill but refrained from doing so because some LDP lawmakers argued the change would lead to a collapse of the marriage system.
The LDP and the Justice Ministry are set to jointly compile measures aimed at “protecting family bonds” within a year.