Karin is a housewife who lives a comfortable life, married to an elite businessman. Currently, her husband is on a business trip abroad, and she is living with his younger brother. Unlike his older brother, her brother-in-law is incompetent and can't hold down a job, so he's been living with them for a long time. Driven by jealousy of his brother and a secret affection for Karin, he hatches a wicked plan. Karin, from a good family and somewhat naive and naive, easily deceived…