Blind Devotion

Young Hwa-Rim, having freed Jin, a serpent god sealed away by a shaman, has her body taken over by him, and the shaman sacrifices her own life to save Hwa-Rim. Years later, now a high school student, Hwa-Rim lives in hiding, constantly on the run from Jin, who is still relentlessly searching for her. One day, Bong-Gil, a classmate of hers, is possessed by Jin, and Jin attempts to use Bong-Gil to track down Hwa-Rim...

(Source: Naver, translated)