Chain Reaction
People are disappearing one after the other in the town of Lovely Hills - Mr. Mariyama is sent to Hell by his daughter who hates him for scolding her. A woman named Akiko sends her husband to Hell because she regrets marrying him. Then Akiko's friend sends her to Hell, because she's always hated Akiko, and so forth. All of the disappearances are blamed on Takuma. While the disappearances are happening, Detective Meshiai goes to the library and finds the book written by Shibata Hajime about Hell Girl.
Aired 24/03/2007EP 24 - Chain Reaction
Hell Girl: Two Mirrors
Ai Enma once again returns as the Jigoku Shoujo, who uses Jigoku Tsuushin (Hell Hotline) to allow people to post their grudges on their tormentors, sending them straight to Hell. In exchange, the users of the website will end up in Hell after they die. Meanwhile, a mysterious girl with blue eyes called Kikuri appears and seems to have strange intentions towards Ai and Jigoku Tsuushin's operation.
(Source: Anime News Network)