Eko Eko Azarak: Wizard of Darkness.

Misa Kuroi is an adorable high-school girl who arrives at her new school when it is falling under an evil supernatural force. Trying to figure out who's behind the supernatural attack, Misa also has to deal with assumptions by her fellow classmates that believe she is the one behind it all. Misa and twelve other students are kept late after school hours one day to retake an exam. Then, after sunset, the entire school is deserted, and the students find themselves trapped inside and their teacher no where to be found. One by one, the thirteen students are picked up and disposed of in horrific and graphic fashion. It is up to Misa to try and gain the trust of her fellow students so that she can protect them and stop the evil before it's too late.