Shiori, the top student, one day visits the home of her classmate, Yusei, who is a hikikomori. She is greeted by Yusei's father, Koji. He appears to be a kind middle-aged man but was actually a former yakuza and had his hands in various illegal businesses. Shiori is taken to Yusei's room and ends up being raped by both Yusei and Koji. Yusei himself is also an accomplice of theirs, enjoying such acts so much that he didn't go to school. Unable to resist due to fear, she is forced to comply, but gradually begins to develop masochistic tendencies…
