Neo Purgatory, situated in the sun-scorched southwestern region of the United States, was initially a hazardous nuclear waste deposition ground. This site has now been transformed into a correctional institution for the most heinous criminals until chaos erupted. The inmates have adorned themselves with nuclear waste, triggering mayhem on an unprecedented international scale. Enlisted in the all-female squad for specialized law enforcement missions, the "Guard of Rose," are Maki Aoba, Doris Nicholas, Marilyn Moreau, and Naomi Jones. Katherine Hook, a clandestine passenger on board, and their multi-faceted robot, Link, join them. During their investigation into rumors of an "angel" sighted near Neo Purgatory, the group's helicopter comes under fire and crashes. With the prison spinning out of control, the Guard of Rose may be the solitary hope in preventing an impending nuclear apocalypse unleashed by the convicts.