Ash, a young man who served as a captain of the Imperial Knights and was engaged to be married to a noblewoman, was living a smooth and happy life that everyone envied. But one day, he was told that his engagement was annulled and he was expelled from the Knights. Fed up with everything, Ash left the Empire and set off for a new land: the Kingdom of Rosebell. In this country, which has achieved prosperity that surpasses the Empire thanks to the power of its dungeon, he makes a fresh start as a hunter and makes a name for himself with his overwhelming skills. Meanwhile, Urca, a junior in the Empire who admires Ash, follows him to the Kingdom. The story of a reversal that will repaint his gray life begins now.