The main protagonist of the manga is a high-school boy named Mirai.  Mirai's uncle convinced his aunt to help kill Mirai's family in order to take their money, he sabotaged the Kakehashi's family car, resulting in it exploding when started, and killing Mirai's entire family. He and Mirai's aunt then adopted Mirai in order to receive insurance money in exchange for taking care of him. Mirai's aunt is shown to be a very cruel woman. Mirai mentions that she was kind to him when he was younger, and only starting abusing him after receiving the inheritance money from his parents' murder. This shows that she is also manipulative.