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

AN INCOMPETENT ADVENTURER'S RACE TO BECOME THE STRONGEST DUNGEON DIVER BEGINS!
Years have passed since dungeons sprung up around the world. When adventurer Amane Rin awakens to a unique skill called "Dungeon Teleporting," the rules can't touch him anymore. This is the tale of how he races to become the world's strongest (and fastest-progressing) adventurer!