One day, new teacher Kou visited the home of Hiroaki, a student who was refusing to go to school. Hiroaki's father, Kenta, welcomed Kou and led him to Hiroaki's room. However, as soon as they entered the room, Kenta locked the door, and Kou was overpowered by Hiroaki and Kenta. Additionally, Hiroaki's brother Daisuke and their uncle Noboru, who were active members of a yakuza gang, appeared along with their subordinates and began to torment Kou. Eventually, Kou forgot his position as a teacher and was transformed into a masochistic slave.
