The Red Zone Republic

Most episodes are self-contained short stories in which the series narrates the suffering of a different individual caused by one or more antagonists. In general during each arc, the protagonists' dramas are explained in detail from the start of their grudges, through the escalation of their torment until it becomes unbearable and they resort to accessing the Hell Correspondence website. Although in general, the client gives the antagonist a chance, he or she usually ends up pulling the string on his or her doll and sending the antagonist to hell. Once they have pulled the string, before taking the antagonist to hell, Ai Enma punishes the person for his or her sins with the help of her companions.

In the first season, the story soon follows a journalist named Shibata Hajime, a former blackmailer, and his daughter Tsugumi who shares a strange connection with the Hell Girl as they investigate the truth behind the Hell Girl. In the second season, a mysterious young girl from Hell, named Kikuri who is able to travel freely between Earth and the Twilight realm where Ai resides, is introduced. Later, the plot centers around Takuma Kurebayashi, a boy who is blamed by his townsfolk for causing disappearances around the town that are in reality caused by the townsfolk using the Hell Correspondence. In the third season, some time after Ai's death, Kikuri returns to recruit Ai's assistants along with a yōkai named Yamawaro, who accepts an old offer from Ai to become her fourth assistant. The story follows Ai's mysterious revival from death and subsequent inhabitation of the body of a young schoolgirl, Yuzuki Mikage.
[edit] Hell Correspondence

The medium through which a client contacts Ai Enma has changed over the centuries. Initially clients would write the names of whom they hated on an ema, which later changed to sending a letter to the address appearing in a three-column newspaper advertisement only visible to those with enough hatred. Once the internet became available, people could access the Hell Correspondence website, otherwise known as the "Hotline to Hell". Soon after, the site was adapted into a mobile version that could be accessed from cell phones.[4]

Each medium can only be used at midnight by one who harbors a desire for revenge against their object of hatred. Should someone submit the name of someone against whom they bear a grudge or immense hatred, and their request is accepted, Ai Enma will take them to a realm of perpetual twilight where she offers them a straw doll, one of her companions, with a red string wound around its neck and describe to the client the details of their contract; should the client pull the string tied around the doll's neck, she will ferry the target of the revenge straightaway to Hell. However, once the client's life has ended, he or she too will go to Hell, and a black crest-shaped mark appears on the client's chest to serve as a permanent reminder of this and their decision to send someone to Hell. However, this mark is no guarantee that the person themselves won't be sent to hell by another client...
[edit] Characters