World's Fastest Level Up (Light Novel) Vol. 1

It has been twenty years since dungeons began appearing all across the world, an incident that coincided with humanity receiving supernatural abilities–all of which transformed everyday life into a living RPG. Amane Rin is one of countless people plundering dungeons with the dream of getting rich quick with his unique skill. Rin is far from capable, though, and is quickly written off as a weak adventurer. However, one day, his skill evolves, taking a new form that allows Rin to break the dungeon system and level up at warp speed! Will this new power make him the strongest adventurer in the world?