Long before the gods descended to the lower world and granted falna to mortals, humanity struggled to survive against monsters that roamed freely. In this age of darkness, a young man named Argonaut, a foolish and cowardly dreamer, aspires to become a hero despite possessing neither strength nor courage. When the king of the capital announces a competition for the title of hero, Argonaut impulsively joins, much to the dismay of those who know him. Accompanied by his sharp-tongued half-elf sister Ariadne and other unlikely allies, he stumbles through a series of misadventures that take him from a labyrinthine dungeon to a fateful encounter with a monstrous minotaur. The story unfolds as a comedic and tragic legend, revealing how this seemingly inept clown became the First Hero whose tale would inspire adventurers for millennia. Key characters include Argonaut himself, whose relentless optimism and refusal to abandon others define him; Ariadne, a pragmatic half-elf who does most of the actual fighting; and a cast that mirrors the main DanMachi cast in appearance but with distinct roles. Narrative arcs include the competition for herohood, the descent into the dungeon's depths, and the climactic battle against the minotaur that cements Argonaut's legacy. The series blends slapstick humor with heartfelt themes of perseverance and the true meaning of heroism.