The main character Luke has been an adventurer for fifteen years, but he could only use the skill Repair. Because of that he was known as the eternal E-Rank, third-rate adventurer. One day Luke was hired for cheap by a hero’s party to do odd jobs when he was forced to bear the consequences, caused by the hero's mistake and was left behind in the labyrinth of a difficult-to-clear dungeon. Luke was prepared for death, but his Repair skill evolved during his survival from the brink of death and Luke managed to escape. Now that Luke had returned alive, he decided to stop doing dangerous jobs and turned over a new leaf. Using his evolved Repair skill, Luke opened up a weapon shop for adventurers in a village with a small dungeon. He aimed for a slow life with his second life. His second life, where he lived quietly and comfortably at least, that’s what he thought, when a major incident shaking the entire country appeared before Luke’s eyes?