In the "This Light Novel is Amazing! 2025" (published by Takarajimasha), the Sneaker Bunko title Who Killed the Hero (Dare ga Yusha o Koroshita ka) took first place in the New Works category and second in the Bunko category.

This novel, originating from the online platform "Shosetsuka ni Naro," follows the knights, monks, and sages who fought alongside the Hero in their quest to defeat the Demon King, as they look back on their adventures and unravel the mysterious circumstances surrounding the Hero’s death. Since its first volume was published in September 2023, it has sparked significant discussion, and in digital sales, it reached the position of "Light Novel New Releases: Historical Sales No. 1" (in the first 30 days of digital sales for KADOKAWA's new light novels). Six months after its release, it sold over 100,000 copies, becoming the "Best-selling Light Novel of 2023" in its genre. Since then, cumulative series sales have surpassed 200,000 copies. The production of its third volume has been decided, and various projects are also underway.

After its first volume was released at the end of September 2023, the series gained attention primarily through social media, selling out immediately and prompting a reprint. Total copies in circulation have now surpassed 200,000. The series also gained attention due to a promotional comment from Yuji Horii, the creator of the popular Dragon Quest series, who said, "What is this about killing a Hero?! I shall give you one more chance to solve the mystery!"

Story

The Hero defeated the Demon King. And at the same time, he—was lost forever.

Four years after the fall of the Demon King, the kingdom that finally achieved peace started a project to compile records of the late Hero's great deeds. Knights Leon, Priestess Maria, and Sage Solon, once the Hero's companions, share stories of his past and adventures—yet all of them avoid discussing the true nature of the Hero’s death. “Why did the Hero die?” Was it the Demon King who killed him, or perhaps one of his companions? A fantasy-mystery that will captivate readers with its mix of heroic achievements and the conflicting emotions of the adventurers and the kingdom.