Ayagari no Kanoka

Monsters - strange creatures that were once called monsters. Mikurube Meguri, a member of the Monster Control Bureau, meets a young hunter named Oekiri Kanoka. The Matagi, who remains in the modern era, serves as a "monster hunter" for the Monster Control Bureau, turning his blade against strange disasters on a national scale. A modern Japanese tale of monster hunting, Kaiba.

(Source: Yanmaga, translated)