SSIS-602 I secretly love my brother's wife.

Inheriting her parents' house and living alone without children, Saki lives happily while modestly supporting her office worker husband. One summer day, while doing housework, a stranger suddenly barges in to rob her. Despite being extremely frightened, Saki realizes that the man is Kyosuke, her husband’s younger brother. Burdened by debt and having been fired from his job, he is desperately forcing Saki. And all he does is stay at home. The filthy brother-in-law, having run back to their parents' house, is a monster with sexual desires.