Natsuo has a crush on his high school teacher, Hina and to get past his feelings he goes on a group date and meets Rui, who he sleeps with, but things become more complicated when he finds that they will both become step-sisters.
Natsuo is unsure of his feelings towards his new classmate. Hina receives a call that makes her emotional, and Natsuo is concerned.
Natsuo still worries about Hina and goes to Kazuyuki for advice. Things don't go as planned when Natsuo tries to show his concern for Hina.
Natsuo and Rui are determined to end Hina's affair and take matters into their own hands, but things don't go according to plan.
Rui befriends a classmate with a notorious reputation, who quickly develops an uncomfortable attraction to Natsuo.
After borrowing a book from the library, Natsuo learns the lesson of crime and punishment. However, the punishment doesn't always fit the crime.
Taku Yashiro
Voice
Maaya Uchida
Yoko Hikasa
Haruka Yoshimura
Konomi Kohara
