In the near future, the Tokyo Police Corporation is locked in a bloody war with the "engineers." These genetically modified super-criminals can bio-fuse their open wounds with weapons, turning self-mutilation into a combat form. Ruka, the daughter of the police chief's murdered right-hand man, is now the top engineer hunter. With cold-blooded efficiency she cuts through the psychotic engineers and tracks down their home base, a truly bizarre fetish club. Nothing keeps her from her sworn duty, even when she finds out the truth behind her father's death.