Gengoroh Tagame (田亀 源五郎) is a Japanese manga artist. Regarded as the most influential creator in the gay manga genre, he has produced over 20 books in four languages over the course of his nearly four decade-long career.
Kôichi is a Japanese man living alone in Berlin. He has no job and hardly any friends. One night Kôichi meets Ryota at a bar which is also a sex club. Ryota came to Berlin to visit a German guy whom he had "met" on a dating app. His high hopes for romance (and marriage?) were quickly crushed since the German was only interested in sex, not even letting Ryota stay for the night. That is why Ryota ended up spending the night in the dark room of the sex club. Kôichi for some reason lets Ryota stay at his apartment. They have sex. Ryota goes out almost everyday to get laid by various local men and comes home to Kôichi's. Increasingly caught up with a strange feeling that is akin to but not quite frustration or curiosity (needless to say, it is not even close to love), Kôichi gradually gives himself up to sex with Ryota.
Yaichi (Ryuta Sato) is a single father and he raises his elementary school aged daughter alone. One day, a foreign man named Mike (Baruto Kaito) visits him. Yaichi has an identical twin brother Ryoji, but Ryoji moved to Canada years ago. They have disconnected since that time. Mike introduces himself as the husband of Ryoji. They are a married gay couple. Yaichi is confused and doesn't know how to deal with Mike.