Assigned to the "Nighttime Regional Relations" department within the Shinjuku Ward Office, Arata Miyako is a fresh government employee. With each of Tokyo's 23 wards having designated one such department, their purpose is to tackle paranormal and occult-related matters. Arata possesses the ability to comprehend non-human languages, a skill that sets him apart from all others. While visiting Shinjuku Gyoen Park, he comes across a youkai who refers to him as Abe no Seimei - the name of an ancient Japanese occultist and diviner.