Man-eater (Hitokui) is, the name given to those who prey and feed on humans, the name of those inhuman creatures who lurk in human societies under the appearance of a human being. Kouichi Shibasaki is one of such beings. One day, Kouichi witnessed, along with an ordinary human girl, another man-eater about to eat a human being. Since then, the two have been relently pursued by man-eaters and have to flee along with Futaba, an agent of the "organisation" tasked with protecting them. Source: ja.wikipedia.org