Life in the bustling city of Orario is never dull, especially for Bell Cranel, a naïve young man who hopes to become the greatest adventurer in the land. After a chance encounter with the lonely goddess, Hestia, his dreams become a little closer to reality. With her support, Bell embarks on a fantastic quest as he ventures deep within the city's monster-filled catacombs, known only as the "Dungeon." Death lurks around every corner in the cavernous depths of this terrifying labyrinth, and a mysterious power moves amidst the shadows.

Even on the surface, survival is a hard-earned privilege. Indeed, nothing is ever certain in a world where gods and humans live and work together, especially when they often struggle to get along. One thing is for sure, though: a myriad of blunders, triumphs and friendships awaits the dauntlessly optimistic protagonist of this herculean tale.