To fulfill a client's desire for a sexual relationship with a close relative, Takagi Takafumi initiates an incest plan. When suspicions arise that his real sister has appeared in an adult video, the brother begins investigating the truth and sets his plan into motion. Unaware of anything, the sister is lured to a massage parlor as a gift from her brother. Unconscious of being secretly filmed, she is talked into accepting lewd massage treatments by the therapist. After being blindfolded, she is penetrated by her brother, who has switched places with the therapist, writhing in ecstasy. One week later, the sister returns and voluntarily confesses to having appeared in an AV. She takes the manhood in cowgirl position, then is taken in doggystyle, climaxing repeatedly.