Recycling collector Zhang Xianling receives a collection assignment and discovers a customer being harassed by the demon Ran Nan when he arrives. On the verge of death, he activates the Earn More Recycling System, awakens his powers, and drives the demon away, attracting the attention of the Demon King Jiugong. The Demon King plans to turn Zhang Xianling's seriously ill younger sister, Zhang Miaomiao, into a demon. At the critical moment, Nana, a company specialist, steps in and saves them both. Zhang Xianling then learns that Earn More Recycling is merely a cover for a secret organization dedicated to eliminating demons. Demon King Jiugong seeks to shed his mortal shell and become an immortal by exploiting the obsessions of all living beings, and he commands seven S-rank demons. To protect his sister, Zhang Xianling becomes a demon-slaying recycling specialist and joins the battle between good and evil unfolding in the shadows of the modern city.