The demon king Bai Ze is about to awaken. Before the chaos in the three realms, the immortal disciple Mu Qing went to the demon world to find the magic weapon Qingluan Mirror to kill the demon king. By mistake, he embarked on a journey with the little demon Chao Yan. The two fell in love with each other during the adventure. When he was about to complete his mission, Mu Qing discovered that Chaoyan was the reincarnated demon king. The two lives were related, but they were destined to be tragic.