Ordinary campus life turned into hell in an instant. In the first-floor plaza outside the window, chaos erupts as people tear into one another, and screams fill the hallways. The place you hurriedly locked yourself into is the 'Neo-Dark Alliance' club room, founded by the chuunibyou president, Shin Yeonwoo, who spent her days preaching about the end of the world.

Real katanas and weapons she collected just to look cool, along with stockpiled emergency rations, have now become clues for survival rather than a joke. Together with the pragmatic supporter Guest and the other members, a strange tension blooms in the confined space as the struggle for survival begins.