After her mother passed away a year ago, Sayuri Hayama (Sari Ito), a girl in her third year of high school, has been dependent on her father Keigo (Mummy-D). Unexpectedly, without any warning, her father remarried. He not only brought back his new wife (Reika Kirishima), but also brought back the other's daughter Yui Shida (Yui Sakuma) home. Sayuri, who was in her rebellious period, naturally couldn't accept it. She felt that she and her dead mother were betrayed by her father, so she got angry. At the critical moment, Yui's sudden kiss touched Sayuri's heart. Since then, her strange sister has developed extremely complicated feelings, and she seems to be attracted to each other unconsciously. In the reorganized family, the story of the girl and the girl is quietly staged...