The supernatural girl Ye Luo accidentally bound a contract with the ninth lord Cang Lan Ye, possessing the ability to forcibly summon the ninth lord, and discovered that this powerful and mysterious ninth lord actually has two forms: humanoid and half-demon. Ye Luo and Cang Lan Ye fought their wits and courage around the contract, and gradually got to know and fell in love with each other in the process of forming an alliance. However, Cang Lan Ye decided to stay away from Ye Luo in order to prevent the half-demon force from getting out of control due to the contract, suppressing the out-of-control force. The relationship between the two also ushered in a new crisis.