Yuusha-sama no Oshishou-sama

Yuusha-sama no Oshishou-sama summary:

After losing his parents, he yearns to become a Knight, the poor boy Wynn Byrd diligently trained himself. However, it was hopeless for him to become a Knight, because his magical power was too low, he can’t pa.s.s the Knight examination so he was labeled with the unpleasant t.i.tle of 『Eternal Knight Cadet』.
But one day the Hero defeated the Demon King 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 my Masters (Teacher) side, Wynn Byrd.」 This is the story about a boy who somehow changed his cla.s.s from 『Eternal Knight Cadet』 to 『Hero’s Master』.