Mysteries of Class 10-B

Class 10-B, the most feared class. Well not because they are like filled with yanderes and gangsters. The students are known as one of the most kind, polite, generous and every positive thing you think. The teachers loved and admired them so much. They are actually Class 10-A at first. When it started.

An unidentified profile started the mysterious activities that made everyone shiver in fear. Murders of students, staffs, and teachers. Chainmails. Creeps. Accidents. Every crime. All of it are present in this class. The teachers attempts to solve and stop this. They never investiagted or even questioned the class since they believed that they can never do it. The students believed it as well.

Just for a while though.