A powerful creature capable of disguising itself as a human and hiding among people. Some call them “Earth Dwellers,” “Underground People,” or “Impostors”... Impostors are roughly divided into three types according to their level of malevolence: ordinary, mutated, and extremely evil, or deranged. Once an Impostor has mutated, a wanted order is generally issued to capture it, dead or alive... The organization responsible for dealing with Impostors is the Arrest Division, which reports directly to the Institute for Paranormal Research. Its Special Operations Team is at the heart of the division... But in the end, no one knows why Impostors appeared...
