Hitokui

is a Japanese light novel series written by Akihiko Odo, with illustrations by Morisoba. The series began publication on November 10, 2004 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
Hitokui-A general term for creatures that are similar to humans and are confused and eaten by humans. Koichi Shibasaki is one of those Hitokui. One night, Koichi and a human girl, Hitomi, happen to see Hitokui preying on humans. The two are relentlessly targeted by Hitokui and others, perhaps because of their mouth closure. Futaba, an "organization" agent who escorts the two, glares that the case is not just a witness's mouth. Koichi realizes that and decides to know the truth ... Human predation, Koichi and Hitomi have no contact at all. When this missing link is connected, an unexpected truth will be revealed! A dark mystery presented with full action that will not breathe.