At the beginning of the semester, Takashi Komuro has a social separation with his childhood friend Rei Miyamoto. When he goes outside to mope, he witnesses a zombie, known as "them", attack at the front of the school. Takashi goes to warn Rei and his best friend Hisashi Igo, who is dating Rei, and escapes with them just before news of the attack spreads across the school, causing panic.