Female guests visiting a hot spring inn are called in by a masseur known for perverted treatments. Unaware they are being filmed, they receive intensely stimulating massages that awaken their deepest desires. The first woman is a married teacher in her mid-twenties. Though she feels guilt, she accepts his penis and writhes in pleasure, surrendering to sensation. The second is a young woman who begins skeptically but gradually grows passionate, convulsing in ecstasy each time he thrusts into her. The third is a sales clerk in her early twenties, her big breasts kneaded until she's overwhelmed. Convinced by his claims of therapeutic benefits, she allows penetration and loses all control, moaning uncontrollably as she drowns in pleasure. Each woman, with a different mindset, endures the intense stimulation while being driven wild by lust.