Sachiko lives with her boyfriend, and both of them really want to have a child, but they feel scared because they have no experience in taking care of children. Her boyfriend has a suggestion to pretend to be a child so she can practice taking care of a child. Sachiko takes this very seriously; she treats him like a real child and takes care of him meticulously, but her massive breasts are constantly in front of him, making it impossible for him to concentrate...