After losing his parents, he yearned to become a knight, the poor boy Wynn Byrd diligently trained himself. Even after parting with his mysterious childhood friend, he trained endlessly. However, it was nearly hopeless for him to become a knight, because his magical power was too low, he couldn pass the knight examination and was labeled with the unpleasant title of Eternal Knight Cadet.But one day the Hero defeated the Demon Lord and saved the world. The Hero was a peerless beauty and she gained attention from the entire world. However, the Hero declared to the world, I will return to the side of m master, Wynn Byrd. This is the story about a boy who somehow changed his class from Eternal Knight Cadet to Heros Master.