Dare ga Yuusha o Koroshita ka

Four years have passed since the Demon King's defeat. To honor the deceased Hero, the now-at-peace Kingdom launches a project to compile his many achievements. The Hero's former companions, the Sword Saint Leon, the Saintess Maria, and the Great Sage Solon, are interviewed. All of them are unclear about the truth behind the Hero's death. Why did the Hero die? Was it the Demon King who killed him, or his companions?