One four room flat for three

A girl (Anna Yamada) is just 14-years-old, but she endures a difficult life. Her parents abuse her at home and she is bullied by students at her school. She doesn't have a place where she can feel comfortable. One day, the girl is kidnapped by a man (Shuhei Uesugi) wearing a mask. The kidnapper names the girl Sachi, while wishing her to be happy. For the first time, Sachi can feel happiness.