Yuri lives in Tokyo with her hardworking husband. One day, her nephew Takashi comes to the city from the countryside to prepare for his entrance exams and asks to stay at his uncle and aunt's apartment for about a week. Yuri happily welcomes this rare guest and warmly takes care of him. However, despite being a serious student, Takashi finds himself captivated by his young, beautiful, and well-endowed aunt. One night, while her husband is away working a night shift, Takashi's suppressed feelings begin to surface, pushing the story into uncharted territory.