Three bodies turn up dismembered in an abandoned underground parking garage, cut apart while they were still alive, and veteran detective Fukami of the East Fukuyama police is certain that the one witness, high schooler Tatsuki Hirokawa, saw exactly who did it. Tatsuki keeps his own counsel: his father, the politician Takeshi Hirokawa, has covert dealings with the parasites, and the boy has started digging into them himself. This spin-off runs parallel to the main Parasyte story with a cast of its own.