The Nocturnal Community Relations Division is a group of people that specialize in solving issues involving terrifying occult monsters of the night that regular humans cannot see. Arata Miyako, a young and inexperienced member of the division, has been sent to the division's Shinjuku Ward Office, where he meets fellow members Theo Himezuka and Kyouichi Sakaki. On his first night, Arata finds himself on a mission where he discovers, to his amazement, that not only do all of the supernatural creatures he once thought were fictional exist, but that he is the only human who can speak their non-human language. Later that night, Arata encounters a fabled monster known as a Tengu, who refers to him as the great Heian-era hero.