The My Sister saga follow Arabella, Cecil and Delia three orphaned girls who are also Kinder (Witches in training) In My Sister the Demon Cecil is possessed by a demon and now Arabella and Delia must learn to live with it a day to day basis as they search for away to exorcise it. But as they get close they discover a secret that may tear them apart and even with the help of the sexy and mysterious Black mage all may be too late.