Ritsuko Kawai, a demure woman in her fifties, constantly craves a thick cock and passionately indulges in masturbation until her voice is hoarse. Her intense desire stems from deep maternal love for her son. Yukari Hirose, a woman in her forties, is equally obsessed with her son, and as their bond grows stronger, she guides her son's cock—once born through her birth canal—back deep inside her. This passionate and tender portrayal of mother and son love unfolds in a series of warm, emotionally charged scenes.