Story
Only at midnight can the 'Hell Correspondence' be accessed.
Here, if you type in a grudge that you can't resolve yourself, Hell Girl will appear and send the person you hate to hell.... It was a rumor like an urban legend that spread among children, but it was actually true.
Her name is Ai Enma. When the normally inconspicuous girl sympathizes with the feeling of a grudge, she transforms into Hell Girl!
...But there is a contract with the girl that wasn't mentioned in the legend.
"When one person is cursed, two graves are dug, so in exchange for sending them to hell, your soul will also go to hell after death, are you alright with that?"