Rhys quickly adapts to his new environment, utilizing his Scavenging skills to collect potion dregs while plotting revenge against the bullies who murdered his body's previous owner. When the fat ringleader Tam, the skinny Den, and the burly Bast return to the cliffside to gloat, they find Rhys alive and digging through the refuse like a rabid dog. Rather than cowering, Rhys constructs a shaky three-legged chair to climb near the edge and prepares a devious pitfall trap. He lures Tam and Den into a deep hole seeded with breadcrumbs, trapping them with a swarm of flesh-eating rats, mice, and spiders. When the formidable Bast, who possesses natural mana control, watches in amusement, Rhys springs from a nook with mana-enhanced speed and presses a broken three-inch sword blade to the boy's throat. Recognizing Bast's potential and his distaste for bullying the weak, Rhys offers him a partnership, promising to climb to the apex of the world. Bast accepts, joining the self-proclaimed God of Trash as his loyal bodyguard. Together, they exploit a regional martial tournament, posing as official cleanup boys to snatch discarded potion vials and sell them for gold, while also crafting fashionable bags from ruined mages' robes. Their highly lucrative scalping operation is interrupted when an angry adventurer named Untor accuses them of sabotage. Rhys deliberately retreats to the orphanage, baiting Untor into launching a violent attack in front of elite mages from the Snowdrop School. Rhys plays the victim perfectly, using his new Blow Mitigation skill to survive the blow while the mages ruthlessly subdue Untor for violating their laws, securing Rhys' safety and establishing his reputation as a brilliant, albeit weak, schemer. Soon after, they are approached by a mysterious, dirt-covered expert known as the Strawman, who offers to take them both as disciples. They abandon the orphanage under the cover of night, stepping onto a brutal training path that will push Rhys' fragile body to its absolute limits, leaving him to wonder what kind of monster their new teacher truly is.

Rhys and Bast spend two grueling years wandering the wilderness under the tutelage of the Strawman. While Bast excels at direct physical combat, Rhys struggles to keep up, constantly getting beaten by their master's flexible birch stick. Despite his trash-tier talent, Rhys learns to circulate his mana without fever and begins developing Trash Intent, the ability to manifest the ideal form of discarded objects. The peaceful training halts when they enter a town and discover wanted posters labeling their master as an extreme danger. The Strawman is actually a legendary Remnant, a cursed effigy created by a demon king three hundred years ago, capable of absorbing immense despair and converting it into catastrophic curse power. Righteous mages from the Bramble School trap the Strawman in a powerful purification array, prompting him to transform into a colossal, pitch-black straw monster that easily corrupts the surrounding mages. The Celestial Rose Maiden, Lady Illya, intervenes, turning the town into a raging battlefield of giant, toxic roses. As the world-shattering clash threatens to fry Rhys' brain from sheer magical complexity, a mage named Alistair whisks the disciples away. They are brought to a mountaintop platform where representatives from the continent's premier schools gather to recruit the survivors. The legendary Sword Saint, Luc Sion, personally takes Bast as his disciple due to his incredible Fist Intent. Rhys, dismissed by everyone as untalented junk, is left behind until Magus Aquari Gibron, the schoolmaster of the bottom-tier Infinite Constellation School, takes him in as a literal janitor, separating the two foster brothers. Rhys watches his friend depart toward a glorious future, while he is carried away on a flying sword toward a mountain that reeks of rot, ready to rebuild his destiny from the literal garbage of a failing school. He swears that he will not remain at the bottom forever, and that one day he will grow strong enough to unseal his master and stand at the very apex of the world, even if he must crawl through the filth to get there.

At the Infinite Constellation School, Rhys embraces his janitorial duties, clearing the mountain of toxic alchemy waste and rotting herbs. He establishes a secret trash pit in a deep ravine, where he discovers that burning trash releases thick, impurity-laced mana. While other mages desperately avoid impurities because they clog mana passages and stunt growth, Rhys realizes that impurities are simply another form of trash. He steeled himself and sucked the impurity-laced mana into his core, suffering immense pain as his veins and organs began to rupture. He manually reconstructs his damaged body using the clean energy released by burning the impurities, unlocking Trash Body and establishing a highly efficient cultivation loop. He refines a super-pure mana alloy that makes his magic vastly more powerful than ordinary Tier 1 mages. His herbalism talents impress the potion master, Sorden Tagg, who buys his high-purity herbs for bags of gold and tasks him with growing a legendary Star Ice Seed. Rhys also provokes the martial instructor Cynog, resulting in a brutal beating that forces Rhys to sacrifice his own foot to escape into the library. There, he is saved by Az, a lazy librarian who is actually a powerful cat-beast. Rhys achieves a breakthrough in a mustelid class, unlocking the defensive spell Cornered Rat. He begins sparring with Ev, a powerful Tier 2 crossdressing martial artist who is hiding her strength from the school's corrupt leadership, using her as a training partner to refine his newly gained skills and test his limits against a serious opponent. He begins concentrating the toxic cauldron gunk into a highly concentrated filth potion, pushing his body and mana passages to their absolute limits as he prepares for the arrival of a dangerous guest. The black smoke billowing from his training ground sparks rumors of an ancient undead monster among the terrified disciples, who begin leaving offerings at a makeshift shrine, completely unaware that their feared deity is merely a teenager brewing highly concentrated sewage in a broken pot.

The peace of the school is shattered when Ernesto Almet, a haughty guest teacher from the powerful Purple Dawn Academy, arrives with four elite disciples: Victor, Hono, Mae, and Walter. Purple Dawn holds massive debts over Infinite Constellation School and intends to find any excuse to shut it down and seize its land. To humiliate the school, Ernesto proposes an inter-school exhibition duel against their best students. Cynog, seeking petty revenge, nominates Rhys as the school's sole champion. Rhys steps onto the golden grid, facing Victor first. He easily humiliates the arrogant boy by summoning his savage rat projection to tear into Victor's face, then kicking him out of the ring. Next, he faces Hono, a goth-lolita curse mage who tries to permanently cripple him with toxic dark energy. Rhys simply absorbs her curse power to refine his own mana, then knocks her out. The third opponent, Mae, is a powerful martial artist who uses a hidden barrier shield and throws caltrops. Rhys uses Trash Step to navigate the caltrops and impales her shoulder with a Trash-Intent steel pole pulled from his storage ring. Now, Rhys stands bleeding and exhausted, facing Walter, the elite noble disciple of Purple Dawn who is on the verge of ascending to Tier 2. Rhys uses his masterclass shit-talking and psychological manipulation to shatter Walter's righteous confidence, forcing him onto the moral back foot before they clash in a final, desperate battle. With his mana running dangerously low and his body held together only by Trash Body, Rhys must find a way to survive Walter's flawless swordplay, knowing that the survival of his precious, trashy sanctuary hangs entirely on this final encounter. He braces himself as their blades clash, his wrists singing with pain as Walter's relentless strikes begin to dismantle his desperate defenses, leaving him to wonder if his trash-tier foundations can truly weather the storm of a true noble genius.