Zero was the imaginary friend of a girl named Alice, she was really protective when the young girl was bullied by some other kids, but then she was believe the parents of Alice will not let them play anymore. So, after little Alice was sat on the grass, she make her go on the midle of the street when a car pass on, Alice see it was the car of her beloved parents, and was not know that Zero had murder her parents because she was fear to not play with her anymore.
So Alice seem to have locked her up from her imagination, and make a real friend instead of her who is named Ann, so Alice tought she had forget all of her problems, then Alice feeling sick and go to the bathroom and splashed water on her face and sees she had blinking at herself in the mirror. When Alice return to class she cut herself and red blood stain drop on her school work, then she return after walking with Ann she heard Zero voice in her head, Zero told her she had locked her away for too long, and she was her only friend.
Alice was thinking she going insane, but realise who Zero was, and now understand she was the one responsible for the death of her parents. When Alice told her to leave her alone Zero said she was gone for too long, and take over Alice body who had now turn white. So she go look for knive, and cut her face and sew it for stop the blood, then she heard Alice phone ring up and pick up Ann's call.
Then she go to Ann house and knock at the door, then she grabbed Ann arm and throw her on the wall, she told Ann that Alice will never come back and was gone for ever, then she kill the poor girl with a sledge hammer, and draw a zero on the skull. She see the gift from Ann to Alice, when she open up see a white and black stripe scar and thank the death girl for this gift, and disappear in the dark wood for other victims.