Souta Konoe, who had been summoned to a different world and led it to peace as a hero, was once a third-year junior high school student. However, during the subjugation of the demon king, he underwent repatriation magic and returned to Earth with all his memories up until that point becoming hazy. Several years have passed since then, but Souta has remained devoted to martial arts training as a senior high school student. One day, while in class, he was once again summoned to another world, this time the same one he had been in before, but a thousand years later. Confused by his memories from before, Souta decided to embark on a new adventure to uncover the truth.