Compared with his classmates, Hadzime Nagumo is the most ordinary guy. He has neither ambitions nor aspirations in life, and his classmates call him "incomplete." Then all the students of his class were summoned to another world in order to save the country from destruction. All the newcomers were given unusual classes and cool abilities—everyone, except Hadzime. He was assigned a craft class called "Synergist," considered mediocre. While exploring the dungeon, Hadzime falls into a pit. What awaits him at the bottom and can he escape and survive?