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.

A boy who lives with his parents in Kyoto comes to Tokyo for a business trip and stays with his fuck buddy. They have no special plans for the five days together. They will go to work in the morning, come home, spend the evening together, and sleep. The first night when he arrives, the fuck buddy starts to have sex with him just as usual, but he is somehow unable to respond. In fact, he has been concerned about a certain thing since before he visits Tokyo.