Alice is a "modern vampire" with the power to manipulate humans lifelines/ heartbeat to either soothe/heal or give someone a massive heart attack.
She is apart of a girl gang called Street Angels (not official btw) and she is the main leader of the group when their boss, Usagi isn't around. Usagi is a demon who created the gang for the sole purpose of taking out other gang rivals. Usagi needs Alice for her power as she is personally linked to her herself because she is a demon.
A week before the earthquake , Alice's parents see her fangs when she opens her mouth wide to show them, and they sew her mouth shut out of fear.
After the earthquake , Alice survives but her parents are buried under the rubble. Alice is found crying with her stuffed animal rabbit, but the string around her mouth has broke and a passing demon sees this. Usagi is a demon of greed, lust, and the desire to break things once they are fixed.
Alice has been hit with a chunk of rubble and she is dying.
The demon comes to Alice and offers her a family in exchange for her services as a "Life Stealer." Alice is a child and only knows the pain and loss of her parents so she agrees. The demon then kisses the child and the string dissolves, but there are scars left over.
The demon possess her rabbit and Alice's hair turns white, forgetting what the demon looked like, but her words are ingrained in the child's mind.
Alice is found and brought to an orphanage, but she becomes a problem child because she wants a real family. She remembers the demons words that she will know when she has found her "true family" and so Alice continues to deny any adoptions. Her scars also save potential parents away because they don't want to have to deal with that.
She physically harms people who come too close to her so in time no one requests her anymore.
Finally in middle school she stumbles upon the gang,(Street Angels) created by Usagi little does she know, after getting in a fight with her orphanage overseer.
There she meets Usagi, the leader of the gang. Alice does not know however that Usagi is actually the demon who gave her life again, and Alice is the one who must serve her in her own way.