Tsutomu, a young man living with his brother and brothers wife, spends most of his days helping out at the family flower shop. Unfortunately, with the head of the household away on business trips more often than not, the nights are pretty lonely for Tsutomus sister-in-law, Mai. As she is coping with that fact in her empty bed one evening, Tsutomu ends up stumbling across the scene and helping her fulfill her womanly desires. But when Mai acts like nothing happened the next day, the frustrated Tsutomu takes matters into his own hands.