Several months after the eldest son, Tatsuya, started living in Tokyo, Kayoko Iba lived a modest life with her second son, Takumi. Tatsuya is strong-willed, while Takumi can be timid, but both were born from Kayoko's 'easy delivery' hips and grew up without ever catching a cold. One day... news came that Tatsuya would be returning home during a break from work. Excited by her eldest son's long-awaited visit, Kayoko vigorously cleaned the house while shaking her ample buttocks, but she was caught in the act by Tatsuya...
