Hiroto has lived with his father since he was young.He longs for his friend's mother, Rieko, who always cares about him, and before he knows it, he feels like she's in love...However, ignorant of her sexuality, he does not know how to calm her excitement, and finally consults her.Surprised by her confession, Rieko secretly teaches him.Obsessed with her first sensation, Hiroto can't stand her and pushes her down, shaking her hips in her gumshara.His relentless rhythm makes Rieko squid many times.