Yuusha Densetsu no Uragawa de Ore wa Eiyuu Densetsu o Tsukurimasu: Oudou-goroshi no Eiyuutan

Yukina was a young man who hailed from the same village as the Hero who shouldered the fate of the world. Through a certain incident, he got ahold of the talking spear, Gram. It was a weapon that was on par with the legendary sword the Hero wielded. The first volume of an adventure fantasy of the youth with a realistic growth!

(Source: Japanese publisher, translated)