因为偶然的机缘,懵懵懂懂的富家子弟车大雄(李胜基 饰)解救了被封印在三神庙一幅画中超过五百年的九尾狐(申敏儿 饰)。这一人一妖的命运从此联系在一起。九尾狐随大雄来到首尔,现代文明让这个神话中的妖怪闹出不少笑话,她聪明非常,极端爱吃肉,为散漫鬼马的大雄生活中增添许多乐趣。随着时光的流逝,他们打打闹闹,竟渐渐也萌生了感情。大雄拥有九尾狐的狐狸珠,这颗珠子吸收100天人气后,会使九尾狐变成人类,然而这却会牺牲大雄的性命。 在这个物欲横流、冷酷冰冷的现代社会中,他们神话般的缘分最终将会如何?Cha Dae-woong (Lee Seung Gi) accidentally releases a troublesome gumiho, a legendary fox with nine tails, sealed inside a painting by Grandma Samshin . Fleeing the scene, Dae-woong suffers a life-threatening fall and is only saved by the gumiho giving him her "fox bead". When Dae-woong awakes and meets a mysterious pretty girl, he initially treats her as eccentric or mentally ill, before fully understanding she is a gumiho in disguise-at which point he tries to research gumihos, but fails to find correct information in the library or on the internet. He agrees to stay with her and he tries to keep her happy, while hiding her true identity as a gumiho from all others by introducing her as his friend, Mi Ho. Slowly, however, he becomes less scared of her and more protective of her-finally admitting to himself and to her that he loves her. As the story unfolds, Mi Ho (Shin Min Ah) pursues her goal of becoming human, with the half-human, half-supernatural Park Dong Joo, who has a career as a veterinarian and has been living as a half-human for hundreds of years, informing her that to do so, she must drink his blood and allow a human to keep her fox bead inside their body for a full 100 days - faithfully entering into a Love Contract, and keeping the bead from being harmed by remaining chaste. However, Dong Joo does not mention that at the end of the 100 days the human will die. Mi Ho and Dae Woong fall in love without fully knowing the consequences of fulfilling her goal: namely, that Woong will die if she becomes fully human.