Kurt, a kind-hearted boy, is suddenly kicked out of the Hero's Party for being useless. He discovers his aptitude for weapons, magic, and all combat-related skills is the lowest rank, so he takes odd jobs repairing castle walls and digging for minerals to make a living. In these tasks, his exceptional abilities are immediately revealed, proving him skillful in cooking, building, mining, and crafting magical tools. In fact, his aptitude for every skill unrelated to combat holds an SSS ranking. However, Kurt seems completely unaware of his own talent and ends up saving people, the town, and even the country through his oblivious actions.

The story follows Kurt Rockhans, whose perspective on normalcy was shaped by his extraordinary hometown, making his god-tier non-combat abilities seem routine to him. His journey begins when he partners with Yulishia, a key figure connected to the royal court who recognizes his value. She sells magic crystals Kurt creates to the royal court mage, Mimico, sparking interest in the mysterious boy. The narrative is set primarily in a frontier town where Kurt had previously repaired the walls. Here, his allies establish a new workshop, or atelier, secretly appointing him as its master without informing him due to his naive nature.

The main cast includes Kurt, the protagonist blessed with SSS-rank non-combat skills; Yulishia, who becomes his protector and partner; and Lieselotte Lise, the third princess of Gurumak who is targeted by an assassination plot. Other key figures are Ophelia, a fellow atelier meister; Mimico, the royal court mage; and the mysterious agent known as Bandana.

Several narrative arcs shape the series. The banishment arc begins with Kurt expelled for being weak in combat, only to find success in civil work like rebuilding castle walls in record time, which ironically gets him fired for making others redundant. The assassination plot reveals Lieselotte is cursed and marked for death. Kurt unknowingly lifts her curse with special porridge, forcing the group to protect her while keeping Kurt unaware of both the danger and his own importance. The atelier construction arc sees Kurt single-handedly building a luxurious workshop complete with gardens, self-generating water, and flameless lighting in just three days. When Yulishia installs anti-curse barriers to protect Lise, Kurt washes them away mistaking them for graffiti. Later arcs involve Kurt receiving an egg that hatches into a young girl, helping a village with water shortages, and tunneling into dangerous ruins to save an ally while his companions defeat a demon lord.