Ura-Tokyo: Exorcist City

Beneath Tokyo lies "Ura-Tokyo," a shadowed counterpart to the city we think we know. There, a secret academy trains exorcists to battle evil spirits. After entering the forbidden grove of Madara Shirazunomori Forest, Soma Kuroniwa is cursed to harbor a spirit of exceptional danger. Hiding his true nature, he enrolls in the academy and throws himself into its brutal training program—one with a graduation rate of only a few percent. When a powerful spirit draws near, the inhuman force sleeping inside him awakens.

Source: K Manga