Serina has been married to her husband for three years and is living a happy life. One day, while she was folding the laundry as usual, a masked man suddenly entered the house and raped her. The man's true identity was her husband's younger brother, Koji. Koji has a strong complex about his brother, who is successful at work, lives in a nice house, and lives happily with his beautiful wife. His uncontrollable sexual urges towards Serina drive him crazy.