Mio is 42 years old. While taking a break from her high school reunion, she falls into an affair with Ichijo. Although she knows it's wrong, the sense of immorality of being held by a man other than her husband turns into pleasure, and Mio falls into a spiral of infidelity. As she continues to have sex with Aise, Mio's reason loses control and she offers her anus, which her husband has never penetrated, to Ichijo. "Please forgive me... I can't go back..." A married woman's adulterous affair, drowning in desire.