Kyouya Mitsurugi, known simply as Mitsurugi, is a supporting character in KonoSuba who originates from Japan, having been reincarnated into the fantasy world before the protagonist Kazuma Satou. He is a handsome young man with light brown hair and blue eyes, typically clad in blue and gold plate armor. His adventurer class is Sword Master, and he wields the cursed sword Gram, a powerful cheat item granted to him by the goddess Aqua specifically to aid in defeating the Demon King. Mitsurugi is driven by a strong sense of justice and a desire to become a true hero worthy of Aqua’s gift, which he regards with deep reverence. However, he also possesses a noticeable degree of narcissism and self-importance, leading him to sometimes ignore others’ perspectives and act in a self-righteous manner. Despite these flaws, he is generally polite, well-mannered, and admired by many townspeople and fellow adventurers for his competence and heroic bearing.

Mitsurugi leads his own adventuring party consisting of two female members, Cremea and Fio, both of whom hold him in high esteem and are romantically interested in him. His role in the story is primarily that of a recurring rival to Kazuma. He first appears challenging Kazuma to a duel over Aqua’s companionship, only to lose when Kazuma uses the Steal skill to take his magic sword. This defeat humiliates him, but he later regains Gram and continues to cross paths with Kazuma. Their later encounters also end in Mitsurugi’s loss, often due to Kazuma’s underhanded tactics rather than pure strength. Mitsurugi’s relationship with Aqua is characterized by his unwavering admiration, yet Aqua frequently fails to remember his name, which adds a comedic element to his earnestness.

In terms of development, Mitsurugi begins as a stereotypical “chosen hero” archetype but gradually reveals a more vulnerable side. He is genuinely powerful—capable of slaying an Ancient Dragon with a single blow—but his reliance on his sword and straightforward combat style makes him susceptible to unconventional strategies. During the final assault on the Demon King’s castle, Mitsurugi fights fiercely against the Demon King’s generals, but he is gravely wounded and left incapacitated, ultimately forgotten by his allies in the chaos. This anti-climactic end underscores the series’ satirical take on heroism, showing that even a well-equipped and well-intentioned character can be overshadowed. Notable abilities include his mastery of the sword and the destructive power of Gram, which can cut through almost anything. However, his lack of versatility and occasional arrogance prevent him from reaching the heights he aspires to.