Escaping school offers no refuge for Takashi Kimuro and Rei Miyamoto: beyond its grounds, Japanese society has already collapsed under an outbreak of the walking dead. Their escape follows a devastating loss. When Takashi's best friend is bitten and becomes one of the undead, Takashi must kill him. He then vows to protect Rei, his friend's girlfriend.
The pair join other survivors to search for their families and discover the cause of the pandemic. Their companions include Kendo Club president Saeko Busujima, firearms-obsessed otaku Kouta Hirano, politician's daughter Saya Takagi, and school nurse Shizuka Marikawa. Together, the students and nurse must contend with the undead as they pursue answers in a country consumed by chaos.