Tezuka Ryou

His younger sister committed suicide due to bullying by the heroines, and then he even lost his parents in a mysterious arson attack. In order to avenge her sister's murder--why was her sister the target of bullying?　Who was responsible for the arson? To find out the truth about everything, the boy abducts the three girls who bullied her and locks them in an abandoned mansion.
Originally from a wealthy family, he was left alone in the world and all of his wealth was inherited, so he has no financial difficulties. The mansion in which the heroines are trapped is one of the inherited assets. He and his deceased sister were truly in love with each other as brother and sister and as lovers.