Since the birth of his little brother, his mother Minori's breasts have gotten bigger. Even though his son Yoshio knows it's wrong, he can't take his eyes off Minori's chest. "Those breasts must be full to the brim with breast milk..." The more he thinks of it, the more his fantasies grow. I want to be pressed tightly by those breasts! I want to feel the breast pressure and be bathed in breast milk! Fascinated by Minori's breasts, Yoshio finally opens the forbidden door...