THE NATION’S FUTURE RESTS ON THE BACKS OF A SALARYMAN AND A FAIRY?!Using his mysterious Skillbook ability, former salaryman Mizuki and his partner, a fairy named Kessie, live to fight another day. They’ve both had enough of the dangerous exploring, but a public servant named Tachibana offers Mizuki an official government Dungeon Advisor position.Reluctantly, Mizuki accepts, but the other adventurers he meets despise him for his lack of experience. He heads into a dungeon for some training, but his party encounters a boss slime that has disguised itself as a cave! Against a such a strong foe, Mizuki and his party will have to use their quick wit and their skillbook strategies, but will they be able to save the day?