Replying...
Intro. It all starts with Professor Lee Byeong-chan, who works at the Hyosan High School Laboratory. His son, Jin-S, suffered extreme bullying and tried to kill himself. The father, desperate to "make him stronger," creates an experimental virus that should arouse the instinct of survival and aggressiveness. But something goes wrong: the virus transforms jin -u into a violent monster, which soon becomes the first zombie. Instead of destroying everything, the teacher tries to keep the virus under control - but a student enters the laboratory, it's bite ... and takes the virus into school.

All of us are dead

@Natasha