your daughters are erotically arranged to make children.

You were forced to take care of your daughters when your brother went on a business trip. Gradually you notice a strange thing while taking care of the ugly, bright and pityy girls. These girls were not known to be bad by the hands of their perverted brother, and had been trained in sex. As a matter of course, the day begins when it is hard to continue pouring "o-jiru" in the bath together and the hair of the daughters who are innocently exposing sexual intercourse is born or not yet.