After her father-in-law dies, Hitomi and her husband take over the family bathhouse. The workload leaves them little time together, and she spends her days feeling lonely. Then Manabu, a younger regular who often arrives just before closing, unexpectedly starts working there part-time. As they labor together drenched in sweat, Hitomi becomes secretly attracted to him, and one incident leads them into an affair. The long-forgotten pleasure of a cock awakens the desires buried deep inside the married woman, and her cries echo through the main bath as he makes her climax again and again.