Basara Toujou
Toujou Basara is an ex-member of the Hero-clan. He lives with his two step sisters who are both Demons. Basara is determined no matter what to protect Naruse from anyone wanting to cause harm to her.
Later in the series he starts living with Yuki Nonaka, along side Maria Naruse and Mio Naruse with Zest stopping in occasionally.
He later becomes the Master of Mio Naruse, Yuki Nonaka and Zest.
Later in the series it’s known that he has two mothers, one being a Demon and the other one being a Angel, the last one being Chisato Hasegawa’s Sister, making Chisato his aunt.