A rumor about a seemingly innocent and well-mannered girl secretly offering prohibited services at a supposedly "clean" massage parlor prompted an urgent undercover investigation. Manachan, a new, uniformed girl who claims to still be in training but clearly knows how to handle men, takes the lead—delivering everything from massage and ear cleaning to spooning, and just as the session ends, she immediately offers extra services as predicted. After negotiating down her initial offer of 10,000 yen for handjob and 20,000 yen for blowjob, the investigator agrees to the blowjob for strawberries and pushes further investigation. An additional 30,000 yen secures full intercourse, and another strawberry deal grants permission for filming. To the investigator's surprise, her tightness is unexpectedly loose, unleashing his latent sadistic side. She readily accepts intense acts like obsessive ear licking and choking, allowing him to indulge freely with this premium, slender material. True to the theory that small breasts mean high sensitivity, her nipples twitch and her body spasms with stimulation. In retaliation, she mounts a fierce counterattack with an intense blowjob combining deep nipple sucking and handjob, fully locking into combat mode. Trusting his claim of external ejaculation, she accepts bareback sex in her uniform, climaxing repeatedly as her delicate frame trembles—her mind lost in cock-driven ecstasy, fulfilling his deepest sense of domination. Overwhelmed by the sight of her obedient, writhing obscenity, he can no longer suppress his climax, spurting inside without permission. She freezes in silent regret—but it's already too late.