Thirty years have passed since the world became connected to a mysterious realm known as the Frontier. Nations across the globe now explore this dangerous new territory in search of resources, and with the proper qualifications, even ordinary civilians can pass through the gate to become Adventurers—a new profession born from the practice of retrieving and selling valuable goods from beyond the threshold. For Hajime Okita, a man with no connection to this adventuring life, the dream of a quiet, ordinary existence collapses in an instant with a single sentence from his boss: Okita-kun, you don't need to come in from tomorrow. Fired from the black company where he was overworked and left with barely any savings, Okita reluctantly decides to become an Adventurer just to make a living.

On his very first expedition into the Frontier, Okita acquires an unheard-of skill: Alchemy. This cheat-like ability allows him to transmute materials, most notably creating gold, and from this moment, his ordinary life begins to shine with golden light. However, the acquisition of this skill has an unexpected side effect: it triggers a gender transformation, turning the formerly unremarkable man into a dazzling and powerful female persona who becomes known as the Golden Witch, Eleanor Ocean. While the name Eleanor Ocean is used in the manga adaptation, the original web novel also refers to this transformed identity as the Golden Witch.

The protagonist navigates this new existence with a mix of goofball carelessness and genuine financial ambition, though plans rarely go smoothly and frequently spiral into chaotic comedy. The central conflict revolves around balancing the immense power and attention that comes with alchemy against the protagonist's desire for a stable and prosperous life. As the Golden Witch, the protagonist quickly becomes the focus of national attention, drawing the interest of adventurers, politicians, and criminal organizations alike. The story unfolds across several notable narrative arcs. The early chapters establish the protagonist's firing, first venture into the Frontier, and acquisition of the alchemy skill. A significant story arc involves a trip to the Kuuneru Ruins for leveling purposes, during which Eleanor saves journalist-disguised A-rank adventurer Yoshino Saegusa, who is later revealed to be the guild master's cousin. This event leads to encounters with other adventurers, including Nanaka Yokokawa, whom Eleanor heals accidentally. A later arc sees Eleanor travel to the Diana Mine to rescue Nanaka from the Black Dragon Group, a shadowy organization that has kidnapped her. There, Eleanor teams up with two American A-rank adventurers, Harry and Claire, to defeat the enemy. This success leads to a new complication when a member of the Diet, Shindo, appears at the Ikebukuro branch of the Adventurer's Guild and tries to force Eleanor to sell her newly dropped level 2 recovery potions to him, a request the Golden Witch flatly refuses.