Tian Xiao, a veteran fighter from a post-Apocalypse world, makes his final wish before dying to become an ordinary person and live a peaceful life. He reincarnates as a seven-year-old primary school student in a new world called the Peaceful World, where living people are common and strange shadowy entities known as Black Mist occasionally appear. Despite his adult combat experience, Tian Xiao struggles to adapt to childhood social dynamics, particularly when he brutally rejects a classmate's confession by stating he only likes strong, burly fighters.
Tian Xiao discovers he can perceive Black Mist entities that ordinary people ignore. His new mother, a beautiful but eerie woman who appears to be a ghost, takes care of him and feeds on Black Mist, which she consumes as food. Tian Xiao learns to accept this unusual arrangement, finding comfort in having a mother figure after being an orphan in his previous life. He also discovers a system space within his consciousness—a remnant from a defeated Black Mist that once belonged to a cross-world Tasker with a System.
The story's first major conflict arises when a Black Mist, having grown stronger and developed tentacles, possesses Cen Shishi and captures Tian Xiao's classmates and teachers inside its body. The Black Mist had bonded with Cen Shishi after she expressed a desperate wish for people not to abandon her due to her parents' impending divorce. Tian Xiao rescues Cen Shishi by entering the Black Mist, learning that the consumed individuals are trapped in a dream-like state. Together, Tian Xiao and Cen Shishi defeat the Black Mist by tearing out the tentacles binding them, with Tian Xiao absorbing much of the pain so Cen Shishi can endure the process. After the rescue, Tian Xiao captures the weakened Black Mist to feed his mother.
While preparing the Black Mist as knife-shaved noodles, Tian Xiao is pulled into the system space for a battle in his adult form against the Black Mist's shadow. He defeats the entity and shatters its System, gaining access to the system space's functions. He learns the space can set environments, establish rules, and pull targets into battles, but requires energy to operate. Tian Xiao sees potential in using this ability for various purposes, including a future career in entertainment.
The narrative takes a darker turn when Tian Xiao experiences time loops. A white light descends from the sky and destroys his school, killing everyone including himself. He then restarts, retaining memories of the destruction. Tian Xiao attempts to prevent the catastrophe by creating a fire alarm to evacuate the school, but the white light adapts and targets him directly. After dying multiple times, he learns to use the system space to absorb the white light's energy, which partially charges his abilities.
The white light's arrival coincides with the appearance of a massive corpse in a nearby park, covered in beautiful flowers and symbols. The corpse emits spores that cause hallucinations and mutate the environment, growing mushrooms that drive people into frenzies. Tian Xiao harvests these mushrooms for his mother while trying to protect his home using quicklime to inhibit mushroom growth. The story ends with Tian Xiao navigating this increasingly dangerous new world, balancing his desire for an ordinary life with the supernatural threats that continuously emerge, while caring for his ghostly mother and dealing with the aftermath of the white light's arrival.
