Tokyo Metropolitan government will start a system that effectively allows same-sex marriage in Japan's capital in the next fiscal year from April, Japan's Kyodo news wire reported Tokyo Governor Yuriko Koike as saying on Tuesday.
The local government for the city with a population of 14 million plans to introduce "same-sex partnership" after its local assembly unanimously called for such a move, Kyodo said.
Some local wards in Tokyo as well as some other local municipalities have already introduced a similar plan that officially recognises same-sex couples.
But critics say LGBT couples still face disadvantages in areas such as taxation even under such partnership arrangements.
A local court in Sapporo in northern Japan ruled in March that same-sex couples not being able to marry is "unconstitutional," the first ruling in Japan on the legality of same-sex marriage.