is a Japanese light novel series written by Ezogingitune and illustrated by DeeCHA. It was serialized on the user-generated novel publishing website Shà Âsetsuka ni Narà  from June 2018 to January 2021. It was later acquired by SB Creative who began publishing it under their GA Novel imprint in February 2019. A manga adaptation illustrated by Chako Abeno and with composition by Kitsune Tennà Âji began serialization on Square Enix's Manga Up! manga website and app in August 2019. An anime television series adaptation produced by Gekkou is set to premiere in July 2026.
The Hero Party consisting of the Hero Erik, Warrior Golan and Mage Luck manages to defeat the demon lord named the Majin Ruler who had invaded from another dimension. However, large hordes of demons named Majin continue to advance. Sensing the impending danger, Luck tells his friends Erik and Golan to flee, remaining alone in the space between the dimensions to continue to fight the demons and hold the line until they can reach safety. After fighting so hard that he loses track of time, Luck manages to defeat all the demons and protect the world. When he returns, ten years have passed and he is hailed as a hero and a Great Sage. After reuniting with his friends, he must choose a new path in life, starting with a clean slate. But in the midst of one of his quests, he bumped into Sia Wolcott, a Werewolf hunter hunting vampires.
Written by Ezogingitune, I Became a Legend After My 10 Year-Long Last Stand was serialized on the user-generated novel publishing website Shà Âsetsuka ni Narà  from June 21, 2018, to January 15, 2021. It was later acquired by SB Creative who began releasing it with illustrations by DeeCHA under their GA Novel light novel imprint on February 15, 2019. Seven volumes have been released as of July 2022.
A manga adaptation illustrated by Chako Abeno and with composition by Kitsune Tennà Âji began serialization on Square Enix's Manga Up! manga website and app on August 3, 2019. The manga's chapters have been collected into eighteen volumes as of October 2025. The manga is published digitally in North America by Comikey and by Square Enix via their Manga Up! Global app.
An anime television series adaptation was announced on October 2, 2025. It will be produced by Gekkou and directed by Hiroyuki Kanbe, with series composition handled by Mitsutaka Hirota, characters designed by Majiro, and music composed by Tomotaka à Âsumi. The series was originally scheduled for April 2026, but was later delayed "to present an even more enjoyable work for everyone". It is set to premiere in July 2026.
By May 2025, the series has over 4 million copies in circulation.