Hell Girl: Two Mirrors(2006)

Jigoku Shoujo: Futakomori

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)