Three years after marrying her husband, Serina is living a happy life. One day, when I was folding the laundry as usual, a masked man suddenly came into the house and was raped. The real identity of the man was her husband's younger brother, Koji. He has a successful job, lives in a nice house, and lives happily with his beautiful wife... He has a strong complex about his older brother, and his uncontrollable sexual urge for Serina drives Koji crazy...