Eugene, a hero, is forcibly reincarnated by the Demon King Venomzard. In a world far in the future, he becomes a noble boy named Julius. Freed from his hero mission, Julius decides to enjoy his second life and his school life. However, his brother, Gaias, mocks him, and his parents and teachers consider him a failure. Having been reincarnated with the immense power of his previous life, Julius unknowingly becomes a warrior.