A massive floating structure known as the Sphere is home to a wealthy society that discards its unwanted people and objects into a seemingly bottomless chasm called the Pit. Below lies the Ground, a lawless wasteland covered in endless trash where the abandoned waste of humanity has mutated into vicious monsters known as Trash Beasts. Rudo, a teenager from the slums of the Sphere who makes a living salvaging what others throw away, is falsely accused of murdering his foster father Regto. His conviction leads to a brutal punishment: he is thrown into the Pit. Surviving the fall, Rudo awakens on the Ground and is immediately attacked by Trash Beasts before being rescued by Enjin, a member of an organization called the Cleaners.

On the Ground, emotions and attachment to objects can generate a spiritual energy called anima. When someone treasures an object deeply, it can transform into a powerful weapon called a Vital Instrument, wielded by individuals known as Givers. Conversely, the anima of discarded and hated objects can create Trash Beasts. Rudo discovers that he is a Giver and that the gloves gifted to him by his slain foster father are his Vital Instrument, capable of awakening the latent power in other discarded objects. Driven by a burning desire for revenge against the true murderer and those who condemned him, Rudo reluctantly joins the Cleaners, a group of Givers who fight Trash Beasts and maintain order. His mentor is the short-tempered but skilled Zanka, and he fights alongside other Cleaners including the cheerful Riyo.

The first major arc sees Rudo adjusting to life on the Ground and learning to master his powers during missions for the Cleaners. This includes a mission to the desert tower of Penta, where the group encounters a reclusive girl named Amo. Amo possesses a pair of boots that are part of the Watchman series, a set of legendary and immensely powerful Vital Instruments to which Rudo's gloves also belong. Before much can be learned, Amo is kidnapped by a rival faction known as the Raiders.

Led by the ambitious Zodyl, the Raiders are a group of Givers who oppose the Cleaners. Zodyl is obsessed with reaching the Sphere and captures Rudo to learn how he survived the fall. Zodyl reveals that the Border separating the Ground from the Sphere is actually a living entity called the Watchman, which kills anyone who tries to cross. He has constructed a massive, flying artificial Trash Beast designed to bypass the Border, with Rudo's unique power being a key component of his plan. Rudo refuses to cooperate, leading to a climactic battle on board the beast as it flies toward the Border. After the battle, Zodyl escapes, and Rudo learns a devastating truth: his surname is Surebrec, the same as the legendary Watchman, hinting at a deep connection to the world of the Ground and its history. With new mysteries about his origin and the fate of his friend Amo unresolved, Rudo commits himself to the Cleaners, determined to uncover the secrets of his lineage and the truth of his world. A second season has been commissioned to continue the story.