The five of them (Rantaro, Kaede, Miu, Kokichi, and Tsumugi) all live together, after they were put into a killing game with 11 other students when they were 16. Afterwards, it turned out to be a simulation, but they still have injuries relating to how they died. Rantaro has memory issues from being hit with a shotput ball to the head, Miu and Kaede both can't talk as they were both strangled to death, and Kokichi and Tsumugi are both in wheelchairs due to being crushed. They are all 19 now.