Ryo's parents are away on a trip and he's spending the weekend alone. On his way home, he happens to bump into his friend's older sister, Rena. Rena had run away from home after a fight with her husband and couldn't go back to her parents' house, so he decides to stay at Ryo's house. Ryo has been attracted to Rena's mature sex appeal since he was a child, and in his excitement, he has a wild fantasy... Rena, unaware of this, teases him with her defenseless appearance, but Ryo, who has reached his limit, waits until Rena falls asleep and starts to secretly fondle her voluptuous breasts...