Yuri, three years into her marriage, lives with her husband and his father at his family home. Though her days seem ordinary, her sex life has dwindled to just once a week, leaving her unfulfilled. Sensing her dissatisfaction, her father-in-law begins to make his move, slowly taking control of her desires. In the living room, at the entrance, in the dining area, the bathroom—every corner of the house becomes a place where he dominates her anally, relentlessly training her tight ass. Through this intense in-house discipline, Yuri falls completely into the depths of anal pleasure, surrendering entirely to her stepfather's lust.