The narrative unfolds in a uniquely structured, secluded prison housing an eclectic group of inmates: a seemingly virtuous young man, a captivating woman, a middle-aged ex-soldier, a young female anime enthusiast, an enigmatic elderly man, and a cat. One day, an unexpected power failure unlocks all the cells, releasing the prisoners. However, the guards have vanished, and the inmates are unable to locate any way out. When the old man engages in a peculiar ritual, a strange event occurs, affecting both the prison and its inhabitants.