One night, in the boys' dormitory of the university, a boy mentioned out of boredom that he had seen the devil Satan when he was a child. In order to prove what he said, he found his good friend, who was a powerful wizard. The wizard summoned Satan for them.
The devil Satan fell in love with the cold and enchanting wizard at first sight. In order to get close to the wizard, he began his human life.
The legendary "Moon Bible" was born. The wizard used the power of the devil to find this book, but it triggered a fight for the Nine-Color Holy Stone in the Three Realms. In order to find the Nine-Color Holy Stone, the wizard and the devil signed a contract and began a series of adventures.