To her son, Miki is always seen going about her housework—a sight that holds a special fascination for him, captivating his heart completely. Yet his fantasies go beyond mere admiration, as he finds himself whispering from behind a pillar, "Mom..." consumed by forbidden desire. One day, Miki receives a call from her husband saying he won't be coming home, dashing her hopes of rekindling intimacy after a long time. Overcome by loneliness, she begins to masturbate to ease the emptiness. Unseen, her son secretly records the act, writhing in silent torment. His feelings, once mere fantasy, now spiral into deep, uncontrollable emotion.