A college student who started living alone due to advancing in his studies is an otaku. His sister, envious of her brother's lifestyle, began frequently entering his room. One day, the sister negotiated with her brother to use his room as a place to have sex with her friend with benefits, but was rejected because her brother 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, she awakened to a sadistic tendency. She mocks her brother whose friendship has been destroyed and who has been turned into a masochist.
