Akira secretly fancies his childhood friend Kurumi, but she is in love with his buddy Umezawa. Akira is jealous of Umezawa, but is touched by his solid friendship. The threesome should have spent happy school days despite the uneasy triangle. But one day, some students suddenly start attacking other people, turning into human-eating monsters. In the ensuing chaos, Kurumi and Umezawa also turn into one of those cannibalistic monsters. Cornered by Kurumi, Akira braces himself for her fatal bite, but at that very moment, she comes to herself. But that was just the beginning.