A group of 12 people filed a class-action lawsuit on Friday with the district courts of Tokyo and Sapporo to contest the constitutionality of legal provisions requiring married couples to have the same surnames.

Similar lawsuits have been filed before, leading to separate Supreme Court rulings in 2015 and 2021 affirming that the requirement is in line with the Constitution.

However, lawyers of the plaintiffs in the latest suit stressed that the situation has changed, with lobbyists actively pushing for an amendment and polls showing the public being in favor of nixing the rule.