When Empress Dowager Yang Yuhuan from Tang dynasty accidentally falls down the stairs, her spirit travels to the future into the body of a beautiful young man that has just been hit by a car. The driver works for an architecture company owned by Huan Yi, who looks exactly like Prince Yuan, whom Lady Yang was having an affair with in the past. Huan Yi takes the boy home, thinking he suffers of some sort of aftereffect because of the accident, when he keeps claiming he is Lady Yang. He names him Chang Du (Promise) and he tries to teach him how to live in modern times. Things get complicated when his fiance discovers the unexpected guest in his house...