Saryu Usui cares for her husband Seiichi, who lives in a wheelchair. One day, her husband's best friend, Oki, visits and asks to spend time alone with Saryu to help relieve her exhaustion from caregiving. In truth, Oki has long harbored feelings for Saryu, and while Seiichi sleeps, he moves closer to her vulnerable, defenseless form. Overwhelmed by his warmth and tenderness, Saryu hesitates at first, but as Oki passionately caresses her and thrusts deeply into her again and again, she repeatedly reaches climax. Amid these secret moments away from reality, a new emotion begins to stir between them.