GOS presents a documentary-style incest story. Chinen Mao, a married woman and former GOS employee working part-time as a parts model, is targeted by Takagi Takeshi after her stepson discovers she once appeared in adult videos as a GOS staff member. Tasked by his former superior at GOS, he sets out to fulfill the stepson's desire for consanguineous relations. Under the guise of a hidden camera setup, he captures her as she's gradually aroused—her body teased and stimulated until her shaved pussy is dripping wet. She is penetrated deeply, forced into doggystyle with an eyemask on, making her believe he's a former colleague. Ultimately, she's impaled by her stepson, writhing in overwhelming pleasure as her ecstasy is fully exposed.