The supernatural girl Ye Luo accidentally bound herself to a contract with the Ninth Prince Cang Lan Ye, and gained the ability to forcibly summon the Ninth Prince. She also discovered that this mysterious Ninth Prince, who was in a high position of power, actually had two forms: human and half-demon. Ye Luo and Cang Lan Ye fought wits and courage around the contract, and gradually got to know each other and fell in love during the alliance. However, in order to prevent the half-demon power from getting out of control due to the contract, Cang Lan Ye decided to stay away from Ye Luo and suppress the out-of-control power, and the relationship between the two also ushered in a new crisis.