Yuri lives in Tokyo with her hardworking husband. One day, her nephew Takashi came to Tokyo from the countryside where her husband's parents live to take an exam. He asked to stay at his uncle and aunt's apartment for about a week until the exam, so Yuri was excited to host the rare guest. However, contrary to her aunt's feelings, her nephew Takashi, a horny exam-taker in his prime, was fixated on her young, beautiful, and busty body. Then, one night, when her husband was away on the night shift...!