Life is good for Nikaidou Akira as he spends his days at school alongside his friends and long-time crush, Kurumi. That is, until the day everything changes. Students suddenly turn into frenzied zombies, attacking and gorging themselves on one another. Then just as abruptly, they stop! Or...do they? What caused this to happen? And how can Akira and his friends possibly survive when they don't know who will be the next to turn?