It is revealed how Ai Enma became the Hell Girl. It also turns out that Ai Enma had been buried alive as a ritual sacrifice by Sentaro Shibata, her very own best friend.

Onda Maki is being bullied in class, but she doesn't know who is bullying her. She spends every night typing her classmates' names into the Hotline to Hell engine, but always erases it. Her science teacher Kamishiro tries to help her, but Onda always refuses.Eventually, she finds out that Kamishiro is the one who has been bullying her and sends her to Hell. Onda has a new friend, and as they are working after school on a project, Onda discovers that her friend had been helping Kamishiro bully her.

Michiru refuses her fate to be Hell Girl, and tries to disappear. However, her spirit goes to where she first met Yamawaro, and Ai's companions are waiting there. Accusing Ai of bringing her there, she is informed that it was actually the Lord of Hell who arranged everything.