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. Kenji, who doesn't hesitate to be seen by Eiko's buttocks, takes a glance at him. One day, Kenji accidentally peeks at Eiko's dildo masturbation, which is her daily routine to keep her hips easy. Witnessing her mother's big buttocks, Kenji explodes her love for the buttocks and approaches Eiko's buttocks...
