"I'm an Alchemist Who Doesn't Know How OP I Am" centers on a young alchemist named Roa, who lives a quiet life in a remote village. Roa possesses extraordinary alchemical abilities, though she remains unaware of the true extent of her power. Her skills far surpass those of ordinary alchemists, allowing her to create potions, elixirs, and artifacts with unparalleled efficiency and potency. Despite her immense talent, Roa is humble and unassuming, believing her abilities to be nothing out of the ordinary.

The narrative begins with Roa’s peaceful daily routine being disrupted when adventurers and powerful figures start seeking her out for her alchemical expertise. Her creations, which she considers simple and mundane, are highly sought after for their exceptional quality and effectiveness. As Roa interacts with these individuals, she inadvertently becomes entangled in various conflicts and adventures. Her lack of awareness about her own strength often leads to humorous and unexpected outcomes, as she casually overcomes challenges that others find insurmountable.

Key characters include Roa’s childhood friend, a skilled swordsman who often accompanies her on her journeys, and a variety of adventurers, nobles, and magical beings who cross paths with her. These characters are frequently amazed by Roa’s abilities, though she remains oblivious to their admiration. The story explores themes of humility, self-discovery, and the contrast between perception and reality, as Roa’s unassuming nature contrasts sharply with her overwhelming power.

The plot unfolds through episodic adventures, with Roa’s alchemical prowess serving as the driving force behind many of the story’s events. Her interactions with the world around her gradually reveal the broader implications of her abilities, as well as the growing recognition of her talents by those in positions of power. Despite the increasing attention and challenges she faces, Roa’s primary focus remains on her passion for alchemy and her desire to help others, making her a unique and endearing protagonist.