Hirokawa leads a group of Parasites that includes Reiko and Goto. Their goal is to accumulate political power to establish safehouses where they can secretly kill and consume their victims. Hirokawa becomes the mayor of East Fukuyama City, a relatively small town in Japan with a population of 500,000, near Shinichi's hometown. He wins the election by focusing on a platform of local environmentalism. In reality, Hirokawa is a radical environmentalist who believes that the Parasites' role is to reduce the human population, placing himself one step above them in the food chain.
Despite his involvement with the Parasites, Hirokawa is actually human. He dies after being shot by the military, who suspect him of being a Parasite.
(Source: Wikipedia)
