A dire prophecy from the temple foretells that the newly chosen hero will be ambushed and killed by the Demon Lord's aide during their journey. To prevent this future without alerting the enemy, the神殿 dispatches a young priestess named Ryuis on a secret mission: travel ahead of the hero and eliminate the threat before it can manifest. While searching for a legendary warrior known as the Sword Emperor to assist her, Ryuis visits an adventurer's inn. There, she witnesses a sleeping female swordsman named Arenie single-handedly defeat a group of violent thugs the moment she wakes up. Impressed by her strength, Ryuis immediately recruits her, and their quiet, two-person journey begins.

The story takes place in a standard fantasy world where humanity struggles against the threat of the Demon Lord. The official narrative follows the hero's celebrated public journey, but this series focuses on what happens in the shadows. Ryuis and Arenie travel ahead, secretly clearing obstacles and confronting dangers before the hero ever arrives. As they face difficult battles and support each other through injuries and hardships, they slowly grow closer. However, both girls harbor painful secrets they cannot reveal. Ryuis carries the guilt of being the sole survivor of her village, a place she confesses she helped destroy, while Arenie conceals her own mysterious past and the true source of her incredible combat ability.

After they begin working together, the narrative explores their developing partnership. A significant early arc involves Ryuis finally confessing the truth about her village's destruction, admitting to Arenie that she had come on this dangerous mission expecting to die. Arenie's response helps Ryuis find a new reason to live. Later arcs introduce other characters, including a new hero chosen after the original prophecy is averted, and explore more of Arenie's hidden past and the implications of her power. The story unfolds through their perspective as they navigate their own traumas, learn to trust one another, and find their place in a world that only celebrates the hero on the surface.