To fulfill a client's request for consanguineous incest, Koki Karagi devises a secret plan, which is entirely captured via hidden camera. The project begins with a brother who desires a sexual relationship with his underground idol sister. The sister is introduced to a trusted beauty massage service popular among models and celebrities, and she accepts without suspicion. Possessing a highly sensitive body, she reacts visibly to the intense massage, her expression shifting as arousal builds. Easily stimulated, she arches her hips high when her inner genitals are stimulated, climaxing repeatedly. With her vision blocked by an eye mask, she fails to recognize her brother, who is disguised as an assistant, and allows penetration. Moaning uncontrollably from pleasure, she regains her sight only to realize it's her brother—sending her into panic. Despite her shock, she is persuaded to continue, writhing in ecstasy as he keeps thrusting. She then begins sucking the staff member's penis, escalating into a threesome. Overwhelmed by the pleasure of two penetrating cocks, she screams hysterically, orgasming uncontrollably.