For Kouta and Yuka, finding the bloody naked young girl on the beach would change their lives forever, for better or for worse. Unable to speak or function as a normal human being, she is named Nyu by the duo, and taken into their home in an effort to save her. But what neither teenager knows is that this innocent young girl is actually a killing machine -- an experiment gone terribly wrong -- and it is only a matter of time before the murderer in her awakens again...