Tanizaki Jun

Kota's classmate. He is the only son of the director of Tanizaki General Hospital. His mother left him because of a certain incident and now lives with his father.

He has organized a "mama club" where boys who are interested in sex are introduced to women. He seems to like Kouta, who is in a similar situation to him, and takes him in.

He is not a "cocky" boy, but rather, he is someone who sees things in a mature way. He has few friends.

He calls Kyoko, his collaborator, "Sis".