Rei, the kind and beautiful stepmother, had always supported her rebellious son with care and understanding. However, overwhelmed by loneliness and stress, she began seeking emotional and physical fulfillment through phone sex. One day, her son accidentally witnessed her in the act. Shaking with shock and humiliation, Rei found herself powerless against her son's words, gradually giving in to his increasingly intense demands. For her, he was no longer just a family member—he had become something far more intimate.