Itsuki Otomiya
The former Emperor of the student council and secret boyfriend of the Bronze, Maika. Later, Haine finds out that he is and always has been her real father, and that Kazuhito Kamiya was not. Haine is the result of Maika and Itsuki, but was born after Maika and Kazuhito were married. Though it is given that because Itsuki was incapable of having children and as a result, Kazuhito offered to adopt away Haine to become the Otomiya heir, Kazuhito discloses to Maika that the his actual reason behind adoption was that he was returning Haine to her "real" father. Itsuki remains unaware that Haine is his biological daughter. After adopting Haine, he later falls in love with and marries Ryouka and adopts Ryouka's son Kusame. (Source: Wikipedia)