Thirty years after the Demon King’s disaster, the world is overrun with monsters and dungeons. Adventurers, who prevent dungeon expansion, are now celebrated as heroes. Renji Ishitome once dreamed of becoming an adventurer, but his level cap was only 3, and he could only learn the basic skill Mineuchi. With no talent, he gave up and settled for irregular jobs.

However, his fate changes when he encounters a new item, Skill Breaker, discovered in an unexplored dungeon area. In a desperate moment, using Skill Breaker evolves Mineuchi into Mineuchi (EX), granting him the ability to stop various things with his enhanced skill.

Armed with his once-weak ability, Renji begins his rise to power—dominating dungeons with Mineuchi (EX)!