One day, Yasuo returns home to retrieve something he forgot and catches his wife, Satomi, committing adultery with their son, Yoshio. Overcome with rage, Yasuo feels his chest tighten—but strangely, his cock begins to react, leaving him unable to move. That night, haunted by the scene he witnessed, he resolves to approach Satomi, but ultimately loses his nerve and goes limp. Disappointed, Satomi turns to Yoshio for comfort, telling him he's better than her husband. A complex emotional drama unfolds, driven by the shock of infidelity and Yasuo's inadequacy.