Hiroto has lived with his father since he was a child. He admires his friend's mother, Rieko, who is always looking out for him, and before he knows it, he feels something akin to love... However, he is ignorant of sex and doesn't know how to calm the excitement that is rising within him, so he finally asks her for advice. Although surprised by her confession, Rieko secretly teaches him the ropes... Enthralled by the sensations he is experiencing for the first time, Hiroto can't hold back and pushes her down, shaking his hips wildly. Rieko comes again and again to his relentless rhythm...