Towards the end of their summer holiday, a group of high school students’ peaceful lives are disrupted. Someone named “Admin” adds them to a chat group and forces them to play a killing game. Before they find and remove “the target”, whose identity is unknown, anyone in the chat group who does not reply to other members’ messages will die instantly. Panic strikes as students in the class suddenly die one by one. The place where they should enjoy their youth is turned into a scene of carnage.