A college otaku boy who started living alone after going to college. Her younger sister, who envied her brother, began to frequently enter and leave his brother's room. One day, the younger sister negotiates to rent out her brother's room as a place to have sex with her sex friend, but her younger sister refuses because her friend is coming. My troubled little sister suddenly decides to carry out a vile, cruel idea... Sado's habit of awakening as he pushed his older brother mentally. He mocks his brother's friendship has been destroyed and turned into a masochistic man.
