A mutant girl named Lucy escapes from a secret laboratory. Or rather, she slowly walks out, leaving behind a trail of mutilated corpses, but at the last moment, she is shot in the head, causing her to lose her memory, identity, and ability to speak. Completely naked and helpless, she is found on the beach by her cousin and sister, who take her in and name her Nyu. The secret government organization believes that Lucy is a ruthless killer who poses a threat to humanity, so they send an obedient mutant named Nana, who follows the orders of the laboratory's leader, to capture her.