The leader of Japan's junior coalition party, Komeito, has hinted at the need for debates on legislation to allow same-sex marriage.

Yamaguchi Natsuo was speaking in a news conference on Tuesday after a bill to promote understanding of the LGBTQ community in Japan passed the Lower House of the Diet.

Yamaguchi said the worst case would have been not passing any bill submitted by the ruling or opposition parties, and abandoning sexual minorities.

He said it is important to hold thorough discussions, and to enact the bill with revisions agreed by the ruling parties and some of the opposition parties.

Yamaguchi commented on the recent district court decisions in lawsuits over same-sex marriage. Two courts ruled that Japan's lack of recognition of same-sex marriage is "unconstitutional" and two others said it was "in a state of unconstitutionality."

Yamaguchi said the courts are ahead of the Diet discussions. He said lawmakers should enact the bill and promote further policies, indicating the need for debates on legislation to allow same-sex marriage.

Izumi Kenta, leader of the main opposition Constitutional Democratic Party, said it is regrettable that the bill was not drawn up by the persons concerned but by people with political motivations. Izumi said it disappointed those persons concerned. He added he will raise questions about the bill in the Upper House deliberations.