After fifteen years of relentless training in the mountains, honing the most basic defensive technique known as [Parry], a young man named Noor finally descends to the royal capital of the Kingdom of Clays. His only dream is to become an adventurer, a goal he has held since childhood. However, Noor possesses a crippling lack of self-awareness. He genuinely believes his single, repetitive skill is worthless and that he remains a complete weakling, utterly oblivious to the fact that his obsessive training has elevated his [Parry] to a god-like ability capable of deflecting anything from magical lightning to the strikes of legendary monsters. This profound misunderstanding between his perception and reality becomes the driving comedic and narrative force of the series.

The Kingdom of Clays is in turmoil following an assassination attempt on its princess, Lynneburg, known as Lynne, leaving it vulnerable to machinations from neighboring powers like the Magic Empire of Deridas. Noor stumbles into this volatile situation when he nonchalantly saves Princess Lynne from a rampaging Minotaur, which he mistakes for a simple berserk cow. Grateful for his heroism, the princess appoints Noor as her personal retainer, much to the chagrin of her stoic, sword-wielding guardian, Ines Harness. As Noor begins taking on simple quests with Lynne, his path crosses with a series of escalating threats, including a goblin emperor, a colossal poisonous frog, and the infamous Dragon of Calamity. Each time, he defeats these world-ending foes with a single, perfect parry, only to dismiss his victories as trivial and assume his opponents were weak. His humble and earnest demeanor causes everyone around him to misinterpret his genuine confusion as the modesty of a supreme master.

The narrative arc follows Noor's unwitting journey from an F-rank nobody to the kingdom's secret savior. He receives the legendary Black Blade from the king, an indestructible sword he primarily uses as a shovel. He confronts the Six Sovereigns, the kingdom's mightiest warriors who were once his instructors and who are now stunned by his incomprehensible growth. A major conflict erupts when the army of Emperor Deridas invades, seeking access to a powerful dungeon. Noor single-handedly parries the entire invading force, halting their advance with no understanding of the geopolitical significance of his actions. The season concludes with Noor defeating the emperor's ultimate weapon, solidifying his legend while he remains convinced he has only just qualified for a basic adventurer ranking. A second season has been officially announced, continuing the story of the most powerful man in the world who is utterly convinced of his own mediocrity.