Momoka lives in Tokyo, happily married to a kind and dependable husband. However, she harbors a secret struggle. Her husband, being her first man, possesses a unique fetish—pharyngeal penetration—and over time, her body has become accustomed to having his cock thrust deep into her throat. Lately, though, her husband has suffered from premature erectile dysfunction, leaving Momoka's desires unfulfilled, forcing her to resort to masturbation. Their neighbor, Sawachi, notices her distress and, exploiting her fear through blackmail, coerces her into orally servicing him. Though repulsed, Momoka feels a faint thrill. Sensing her inner conflict between guilt and pleasure, Sawachi escalates his control, eventually violating her throat in front of her husband, dragging her deeper into darkness.