A college student otaku male started living alone due to his advancement in education. His sister, envious of him, began frequently entering his room. She negotiated with her brother to borrow his room for sex with her boyfriend but was rejected because he said friends were coming over. The troubled sister suddenly came up with an extremely evil idea and decided to execute it… As she mentally cornered her own brother, a sadistic habit awoke within her. She mocks her brother whose friendship has been destroyed and who has been turned into a masochist.
