Highschool of the Dead is set in the present day, beginning as the world is struck by a deadly pandemic that turns humans into zombies, euphemistically referred to by the main characters as "Them".
The story follows a group of high school students, the high school's nurse, and a young girl as they fight their way to safety through the deadly streets of Japan during a worldwide catastrophic event known as the "Outbreak".
As the cast tries to survive the zombie apocalypse, they must also face the additional threats of societal collapse, in the form of dangerous fellow survivors, and the possible decay of their own moral codes.