It was a rainy night. A girl in a school uniform named Mitsuru Takada suddenly visits the house of Atsutaka Satou. That day, as she came back from school, her house had become someone else's property. Due to family circumstances, she was passed to many different relatives, but ended up homeless. She sought Atsutaka for help because of the close relationship their late mothers had, and they promised to help each other. Atsutaka was suddenly put into a situation where he has to live with a girl. He hopes that he can get close with her little by little.