Anzu was sold to a wealthy man when she was a child by her mother. She had been kept in his mansion chained down to the floor where she was beaten, raped, and even starved. Even though her mother had sold her she still remained hopeful that one day her mother would come for, which never happened. Tekirai was sent out to kill her master and after the master was killed, Anzu was set free. Anzu tried to go back home but her mother had already forgotten about her and had created a new family without her. Ageha recruited Anzu and Anzu became ranked as the No. 9 hitman of Thanatos.
Thanatos Rank and Weapon:
Anzu is ranked No.9 of Thanatos. Her weapon is a parasol in which she can shoot ice from to her opponent. Although she uses the Parasol the parasol is just a medium for her attacks. Her real weapon is the manipulation of Ice. She has also been known to use her power to 'heal' herself by freezing her blood cells. This actually only harms her more, which Zakuro warns her about. She is actually a transgender.
Anzu is completely head over heels for Tekirai. She want to do all she can to be in his favor and often visualizes herself with him, even though Tekirai still treats her coldly.
Anzu doesn't hate Toneriko or dislike him, but she sees him as a rival for Tekirai's heart. She is still willing to save him or help him whenever he needs it. One time, while she was being manipulated by Edelweiss, she even showed her feelings to Toneriko after Zakuro's death.