あらすじ
There is only one reason for his overwhelming strength... hard work!! Ichitaro, a high school boy with a tendency to become completely absorbed in whatever he pursues, is suddenly transported to another world along with his entire class as summoned heroes. However, the rank he receives as a hero is the worst possible. Deemed useless, he is cast into a prison where time itself has stopped. There, Ichitaro dedicates himself to a single goal: training. For one hundred million years, he relentlessly hones his skills. By the time he finally leaves the prison, he has mastered every sword technique imaginable and become the strongest hero of all. Armed with a versatile divine artifact that others mocked as nothing more than an ordinary stick, and aided by the “Sword Demon” persona born from his extreme training, he overwhelms the world with unparalleled swordsmanship.