The Drifting Classroom : Perfect Edition Vol 1

In the aftermath of a massive earthquake, a Japanese elementary school is transported into a hostile world where the students and teachers are besieged by terrifying creatures and beset by madness.

Out of nowhere, an entire school vanishes, leaving nothing but a hole in the ground. While parents mourn and authorities investigate, the students and teachers find themselves not dead but stranded in a terrifying wasteland where they must fight to survive.