Densetsu no yuusha no densetsu manga

Densetsu no Yuusha no Densetsu summary:

A mythical story with swords and magic centering around one lethargic Roland Empire student named Ryner Lute. After getting dragged into a war and losing many of his friends, Ryner is asked by the soon-to-be enthroned king, Zion Astal, to help rebuild Roland postwar by searching for legendary relics. Accompanying him is a beautiful, capable, yet arrogant swordswoman named Ferris Eris, who is always quick to insult and abuse Ryner. Meanwhile, a new turmoil begins to approach Roland.