For as long as she's been aware, the heroine, without a single relative, lived under care of the state. Both of her parents' faces were unknown to her. In front of this heroine, a young boy appeared. The young boy's name was "Hikaru". It appeared that he was the heroine's twin brother, separated at birth. He had a proposal for the heroine. "Could you go to school in my place?" The heroine was shocked by this crazy suggestion. Furthermore this was an all-boys school. The only high school in this prefecture for delinquents."