On her 16th birthday, Rin, a Japanese schoolgirl, discovers that she belongs to an old clan of powerful mutants. Good thing, too, because on that very day mutant-hostile government soldiers break into her home and kill her parents. Rin is their next target. Strapped down to a table by a hot lady doctor, while wearing her schoolgirl uniform, she manages to escape just as the nurse is about to inject her with a lethal substance.
Later she meets another mutant girl, Rei, who dressed as a cute nurse tells the story of how she was kept in a cage by a traveling freakshow before she joined the other mutants. From the supremely weird and outrageously bloody MUTANT GIRLS SQUAD.