On August 20th, Koyomi Araragi left his home to deliver to Mayoi Hachikuji something she had forgotten, but was unable to find her. He realized he had not done any of the homework he was supposed to do, yet tomorrow was already the term opening ceremony.

Shinobu Oshino realizes that humanity had turned into zombies thanks to the powers of Kiss-shot. Koyomi Araragi shoots up fireworks as an SOS signal, but instead they are surrounded by zombies. However, an unexpected individual arrives at the scene...