One day after Cha Dae Woong runs away from his grandfather, he accidentally frees a nine-tailed fox who was trapped in a painting for about 500 years. He didn't realize what he has done until the Gumiho (nine-tailed fox), who took the form of a beautiful woman, appeared in front of him. Dae Woong was so frightened that he ran away from her and became severely injured. The Gumiho saved him by giving him her most precious bead to share with him the mystic fox strength, as she owed him her freedom. The Gumiho then asked him to help her become human and teach her how to act like one. As time goes by, their mutual relationship grew deeper as they start to fall for each other.