wait really ?! I thought they already did...
Well... Yes, but mostly not at all, actually.
Same-sex marriage is not recognized in Japan. As of 1 August 2020, 55 municipalities and two prefectures issue same-sex partnership certificates which provide some benefits but do not offer any legal recognition.
It's still at the stage where it's like getting a prize for participation rather than actually winning. For instance, since these certificates don't actually offer legal recognition, if your "same-sex partner" is in the hospital, you don't actually have the legal rights of a spouse in that situation at all. You might not even be allowed to visit them when a spouse could, depending on the circumstances and perhaps the people involved I suppose