Henry is a weak young adventurer who struggles to earn enough money to look after his sickly younger sister. His only skill is Evasion, and because it and his attack power are so feeble, his party throws him out. Then he finds a glitch: Evasion lets him slip through walls and reach the end of a dungeon without beating the boss. That means he can collect a dungeon's first-clear reward again and again. With this trick, Henry sets out to clear as many dungeons as he can, piling up stat boosts and rare items as he climbs up from the bottom. The show is a fantasy action adventure built around an underdog who turns a useless skill into his biggest advantage.