Hwayugi follows the story of Jin Seon Mi (Oh Yeon Seo), who was born with the ability to see spirits. One day, she is asked by a strange man Woo Ma Wang (Cha Seung Won) to retrieve a fan from a haunted house. She is blocked by Son Oh Gong (Lee Seung Gi) who asks her to blow out five candles to free him in exchange for protection. Upon doing so, her memory is erased by Son Oh Gong, who runs away.
Years later, Jin Seon Mi, now running a real estate business specializing in stigmatized properties, bumps into Son Oh Gong, who is trying to do good deeds in order to have his immortal status restored by Heaven. Through radical circumstances, Son Oh Gong is now bound to Jin Seon Mi and must protect her from supernatural forces, or risk his own goals. What fate lies ahead for this odd partnership?
