Densetsu no Yuusha no Densetsu

Ryner Lute is a lazy student of Roland Empire Royal Magician's school. One day, Roland Empire goes to war against a neighboring country Estaboole, and he lost his classmates in the battle. After the war, Lute sets out for a journey to search the relics of a "Legendary Hero" at Emperor Sion Astal's command. And he finds out that a deadly curse is spreading through the continent.