Naho is a full-time housewife who works hard at housework for her beloved husband. One day, she asks an electrician to fix the kotatsu, which is not working properly... A few minutes later, as she watches the electrician's crotch as he works under the futon of the kotatsu and throws his lower body out, a strange feeling begins to grow in her Kokoro. And, due to her dissatisfaction with her sex life, Naho can't help but straddle his crotch. From that day on, she becomes obsessed with the charms of the cowgirl position, where she takes the lead while riding on top of him...