After losing her husband, Mami lives with her beloved daughter Yui in the family home left by her parents. One afternoon, a burglar breaks in while Mami is away. The intruder is Sugiura, a coworker from her part-time job who has been driven to crime by crushing debt. Mami returns at the worst possible moment and catches him searching the house, setting the stage for a violent assault in front of her daughter.