Despite being only 11 years old, Estelle never imagined her mother would sell her. But to her surprise, the buyer was none other than Duke Ein Castielo, known to be the only one of his kind in the empire...and also Estelle's father?! Ein's blood-red eyes and magical powers are renowned throughout the kingdoms, and he rules House Castielo with a firm hand. Though she has access to his enemies and brave knights, being his daughter does not automatically make her part of the family.