Mahiro has been married for years to her childhood friend, a man she once admired like an older brother. One day his family asks her to spend a week caring for his injured younger brother Shiro. She has always hated the dark atmosphere of the house and the unsettling stares from her father-in-law and brother-in-law, but reluctantly agrees to go. The injury is merely an excuse to get her alone and use her however they please. Her father-in-law drugs the food he serves, leaving Mahiro unable to resist as she becomes the victim of their rape house for seven days...