Ichinose Rei, a prodigy boy and son of the owner of Ichinose Group, a powerful group that comprise of nearly half of the corporate town, Segawa. But in his childhood he suffers a terrible accident and consequently his gender was switched to a girl. Rei studied overseas until she became a teenager, she entered college very young and holds a doctoral degree, all for the sake of her clan, she expected to be their heir until her father banished her, discarding her due her gender, not allowing her to becoming the heir, but nominating her hateful childhood rival instead. She is given a new identity, Midou Maria, some money and expelled from the mansion. At first Maria thinks in committing suicide, but later she decides to join a young group who plots against Ichinose Clan, where she will do anything to obtain her goal: revenge.