Ryo spends a weekend afternoon alone after his parents go on a trip. On his way home, he accidentally encounters Rena, the older sister of his friend. After fighting with her husband and running away from home, Rena can't return to her parents' house, so she decides to stay at Ryo's place. Ryo has been attracted to the mature allure that Rena exudes since they were young and gets overly excited, starting to have wild fantasies… Unaware of this, Rena teases him in a carefree manner, but Ryo, having reached his limit, starts secretly groping her ample breasts as soon as she falls asleep…
