Mio, who was a model in Tokyo, returns to her parents' house for the first time in a while. The parents are happy to resume for the first time in a while, but it seems that only his younger brother, Jun, has an untidy attitude and stays home without going to school. In that case, I make fun of "If I go to school, I will massage my boobs ...", but that awakens my younger brother's sleeping libido, and the huge breasts are roughly rubbed and vaginal cum shot is made with childish SEX. From that day onward, he will be chased by his unequaled younger brother all the time ...