Part of the Kannage family and the sister of one of the guys killed by Ryuya Kazamaki.
Although she comes from the Kannagi family she belongs to the secondary part of it, thats why her last name is Oogami. Her brother was the only person kind to, but was killed by Ryuya when he, alongside another Kannagi relative, were on a mission for capturing Kazuma. Thats the reason why she believes Kazuma was the responsible for his death. After Kazuma, Ayano and Ren defeated Ryuya she attempted twice to kill Kazuma, with no success, it is then that Michael Harley took his chance and seduced her with the false promise of granting her enough power to get her revenge. She gathered inside her body the souls of many innocent victims, and even killed her own family in order to obtain that power. Michael Harley told that their deaths were not a sin if the goal she was seeking was honorable, but when she finally confronted Kazuma and lost her battle, she realized that those were nothing but lies and fainted in horror. After Michael Harley was finally destroyed she recovered her consciousness and apologized with Kazuma. She´s currently trying to pay her sins as a nun in some abbey near by Tokyo.