Ai Enma

Enma Ai is the Jigoku Shouji (Girl from hell) and is the main character of the series. She tend to wear a black and red trimmed school uniform except when she is ‘working’ when she wears a black kimono with colored flowers (looks a little different in the second series).
She receives request for vengeance through a website which can only be accessed at exactly midnight and only by those who truly was revenge. After getting a request she gives the person a doll with a red string indicating that by pulling the string a contract is agreed to take the target of revenge to hell in exchange for that person going to hell when they die. Enma is assisted by three people Ichimoku Ren, Hone Onna and Wanyuudou.
Each of these assistants can turn into the dolls she gives to the persons requesting revenge. During the first series it is always Wanyuudou that turns into the doll but in the second series it varies between the three of them. She has some strange link to the girl called Tsugumi resulting in what she is seeing being transmitted to her sometimes. Enma has a tragic history that turned her into the hell girl revealed in the later episodes of the series.
Enma appears to have some very strong powers creating complex illusions, teleporting people and in some rare cases fire large bolts of dark energy. Her most powerful ability is to send people to hell, however she only ever uses this when she has a confirmed request from someone.