An Osaka court on Monday ruled that Japan's ban on same-sex marriage was not unconstitutional, dealing a blow to LGBTQ rights activists in the only Group of Seven nation that doesn't allow people of the same gender to marry.

Three same-sex couples — two male, one female — had filed the case with the Osaka District Court, only the second case to be heard on the issue in Japan. In addition to rejecting their claim that being unable to marry was unconstitutional, the court dismissed their claim for ¥1 million per person in damages.

The plaintiffs said they will appeal Monday's ruling to a higher court.