勇者伝説の裏側で俺は英雄伝説を作ります 〜王道殺しの英雄譚〜

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)