Saki and her husband live happily in the house left by their parents-in-law. Although she is in a difficult economic time, her husband still has a stable job, the salary is very good, and the two don't have to worry about a piece of rice. Today, while doing housework, a masked man suddenly breaks into the house and forces Saki to open the safe for him. If it was an ordinary thief, she wouldn't know that Saki's house had a safe, and through her voice, Saki could tell that this was her brother-in-law, Kyosuke. It turned out that due to the accumulation of debts and embezzlement of the company's money, Kyosuke was fired and had no place to live. In desperation, he immediately came up with the idea of robbing his own brother's property! But when he saw Saki's charming body, he not only wanted to rob money, but also wanted to rob this sexy sister-in-law! And since then, Kyosuke has been living in the storage room on the second floor. Every day, Saki brought him rice and water. Whenever he wanted, Saki had to be ready to take off his clothes, satisfying his sexual needs! However, the pleasure of having sex with Kyosuke that Saki's husband couldn't give her. She gradually sank into the quagmire of sensuality, until one day, when her husband suddenly returned home earlier than usual...