Hideki, the steadfast eldest son, and Kenji, the spoiled second son. The two were born from Eiko's easy delivery type, but their personalities were different. While Kenji looks down on Eiko's ass without hesitation, Hideki, as the eldest son, suppresses his feelings of wanting to be spoiled by Eiko. One day, Kenji happens to see Eiko's dildo masturbation, which is a daily routine to keep her hips easy. Kenji, who witnessed his mother's big butt, explodes his love for buttocks and approaches Eiko's butt...
