Watashi no Class no Seito ga, Hitoban de 24-nin Shinimashita.

Synopsis

What happened in the classroom that night?! Kitahara, the Nanjo High School homeroom teacher of class 2-C, is involved in an unbelievable incident triggered by the disappearance of a female student, Tomoe Miyata... What happened to those 24 students, and who is behind this horror?! (Source: Kadokawa, translated)