Called to a hot spring inn, a perverted masseuse skilled in obscene massage sessions arrives, unaware that her clients are being secretly filmed as she exposes their lewd behavior through sexually stimulating treatments. The first client is an office lady secretly anticipating erotic massage, who moans intensely with each thrust of the penetrating penis, surrendering completely to pleasure. The second is a thirtysomething female apparel sales clerk aroused by the indecent treatment, her fair-skinned body taken doggystyle from behind as she writhes and screams in ecstasy. The third is a young girl anxious about her friend returning, quickly accepting the penis and squirming silently, suppressing her moans. Each woman gets drawn into the illicit session under different circumstances, captured in vivid, realistic detail.