Kouichi Sakakibara finds himself in a cursed middle school class, Class 3-3, where students mysteriously die in a series of accidents. He becomes close to the mysterious Mei Misaki, who he is the only one to see, and they work together to uncover the secret behind the curse before the body count rises any further. The season explores the origins of the curse and the strange countermeasures Class 3-3 takes, leading to a deadly conclusion.