37-year-old Saki has a slim, petite build and is four years into a happy marriage. She admits she's weak against aggressive advances—a trait that actually led to her marrying her husband after he pursued her persistently. Though she's never cheated, she often indulges in lewd fantasies during daily life, especially on trains, where she imagines other men and craves excitement. Today, during a lunch date, she experiences her first real act of infidelity. The moment she accepts a man other than her husband, her body reacts uncontrollably, her voice dripping with arousal. The intense guilt and allure unique to married women come vividly to life in this encounter.