Fort of Apocalypse, also known as Apocalypse no Toride, is a survival horror manga set in a juvenile detention center. The story follows a young delinquent named Yoshiaki Maeda who, along with other inmates and guards, becomes trapped within the prison after a zombie-like outbreak. As the dead rise and the facility turns into a death trap, the characters must navigate the locked-down halls, forming uneasy alliances and turning on each other to escape the monstrous threat. Readers enjoy the series for its tense, claustrophobic atmosphere, brutal survival drama, and the gritty, unpredictable nature of both the human and undead dangers.