Raust gets thrown away by his party for being useless, then discovers he's been the reason they survived at all. The moment he stops healing their mistakes and starts fighting his own fight, everything inverts. You watch a broken healer become unstoppable not through a power reveal, but through the simple act of refusing to exist for other people's validation.

Two hundred years after a hero slew the evil Jaryu and saved the world, the healer Raust lives in one of many dungeon cities. Taken advantage of by dishonest adventurers since his youth, he is cheated by his first party, Blades of Lightning, and finally expelled by its leader Margulus for being too weak. Mocked in public and doubtful about his future, Raust gets an unexpected offer from Narsena, a newcomer martial artist who wants to start a party with him. He gladly agrees, and the pair soon win renown by clearing unexplored sections of the labyrinth, though Raust has no idea why Narsena was in such a hurry to team up. Meanwhile, Margulus fails a second time to defeat a poisonous hydra, even with the elite healer Lyra at his side, and Raust is asked to come back to his old party. Leaving his former comrades behind proves harder than he expected, even with a new path and a new partner.