Dare ga Yuusha wo Koroshita ka  

Who Killed the Hero?, 誰が勇者を殺したか, Who Killed the Brave

In this village, there lived a boy with exceptional skills in both swordsmanship and magic. People believed in a prophecy that said a hero would emerge from their village to defeat the Demon King. After eight years had passed, this boy became that hero and successfully defeated the Demon King. However, despite his victory, he decided not to return to his village. Four years later, as his accomplishments were being chronicled in literature, it became clear that he had died shortly after his victory over the Demon King.