While his parents are away on vacation, Koji is left to watch the house. His mother's best friend Miki stops by because she worries about him being alone, and he begins desiring her as a woman. Determined to make any kind of adult memory with her, he sneaks into the changing room and masturbates with her underwear, only to be caught. Instead of getting angry, Miki presses her breasts against him and asks, “This is what you wanted to do with me, isn't it?”...