The struggle for survival between humanity and Parasites continues unceasingly around the world. Unfolding in the shadow of the legends of Shinichi and Migi, another battle for existence is revealed. Fukami, a veteran detective, investigates a brutal mass murder, and is unsettled by the composure of the informant: high school student Tatsuki. The source of that discomfort lies within Tatsuki's family… The tale on the other side of the ageless masterpiece "Parasyte" begins here!