Erika

Kazuya Aoshima, who was appointed as a temporary teacher, is told by the vice principal that if he can solve the problem of Erika Shimeno, who is rumored to be bullied at school, he might have a chance for full-time employment. He starts working towards resolving the issue, but her true nature is...!? A psychological horror!

(Source: Shonen Gahosha, translated)