Iroha lived a modest but happy life with her husband and their adult son, who had just begun his career. Meanwhile, Toyama, a friend her son had been close to during his school days, harbored feelings for his friend's mother. Even when job hunting kept him from seeing her, those feelings did not fade; they twisted into a dangerous obsession. Toyama finally went to Iroha's home, determined to possess her. Without warning, her peaceful life came to an end.