Mayonaka no Occult Koumuin

Arata Miyako is a new government worker assigned to the Shinjuku Ward Office's "Nighttime Regional Relations" department. Each of Tokyo's 23 wards has one such department, which were established to solve paranormal and occult-related events. Arata can understand non-human speech that no one else understands, and he encounters a yōkai (supernatural entity) at Shinjuku Gyoen park that calls him Abe no Seimei — the name of a historical Japanese occultist and diviner.

(Source: Anime News Network)

Note: Includes 7 extra chapters.