A busy mother requests a "rental mom"! The beautiful rental mom Aki arrives. The mother is very satisfied with Aki, who handles both housework and childcare. The son also relies on the beautiful Aki! But one day, the son is laughed at at school for not knowing about sex, so he asks Aki to teach him how to have sex. Aki tells him that it is the rental mom's job to fulfill requests, and teaches him how to have sex, but...