Rin goes to the gym to improve her appearance. However, her husband has no interest in her efforts, and they lead a dull married life. Rin has a slight crush on her trainer, who kindly listens to her complaints about the couple... One day, Rin decides to go to a dinner to apologize for causing trouble to an apprentice! When she heads to the restaurant with Kokoro on the day, she finds a young apprentice who keeps making mistakes waiting for her... He begs her to have sex with him just once, but... this young man is not normal!