Arata Miyako is a newcomer in the Nocturnal Community Relations Division, tasked with investigating cases of occult beings that are invisible to the unaided eye. He is assigned to the Shinjuku Ward Office where he meets his colleagues Theo Himezuka and Kyouichi Sakaki. During his first mission, Arata is shocked to discover that the mythical creatures he thought were merely fictional are, in fact, real. What's more, he is the only human who can understand their language. While on a mission, he encounters a Tengu, a legendary entity who identifies him as Abe no Seimei, a prototype exorcist from the Heian era, even though Arata has no prior knowledge of this history. Regardless, he lends his unique set of skills to the team. Over time, news of Arata's special abilities spreads throughout the occult community, causing the creatures to mistake him for Abe no Seimei. This only intensifies his curiosity about his connection to the exorcist. However, the more he learns, the more he realizes that there are dangers inherent in the supernatural world, some of which stem from his own unique attributes.