In the canonical version, three thousand years after the second war between immortals and demons, the two worlds have been at peace for a long time. Since they were both in the middle world, the human world has experienced tribulations. The relationship between immortals and demons has gradually eased. The immortal emperor and the demon emperor have developed into two realms. The only princess in the immortal world, Yun Xiaowu, made a marriage contract with Jun Xiuyuan, the sixteenth prince of the demon clan, and ordered them to practice in the fairy world after they grow up. The little princess who was pampered and grew up and the romantic prince who is always merciful will happen between them. What kind of story will happen between them?