The mischievous girl, Ling Miao Miao, accidentally enters the mission system of the novel Demon Catcher and becomes a villainous supporting character. To return to the real world, she must complete the system's task-winning over the mysterious and twisted young man, Mu Sheng. Along the way, they team up with Mu Yao, a member of a demon-hunting family, and Liu Fu Yi, a demon hunter. Together, they fight demon and level up. As the missions progress, they gradually resolve the animosity between humans and demons, rewrite the fated ending, and save the world.