What is after death? It's a question asked by many, but doesn't have any answer. Here is Jōichirō Saiba who got reborn in the world of My Hero Academia, after his death. He have the meta knowledge of this world thanks to it being a manga and anime in his previous world. Thanks to the meta knowledge of his, Jōichirō knew that it's going to be rough ride, but he didn't think much about it as he just wanted to do what he likes in his new life, which is cooking. But, fate have other decisions for his life. He met with important people who would become a villain or a hero in the future and he started to change their life for good, unintentionally. The butterfly started to flap it's wings and changes started to take place, his meta knowledge advantage started to be a waste. Did he despair knowing that? Not at all, because he didn't want to be the hero of this world. That decision was also thawed thanks to someone else, and he decided to be hero even for one day. This is his story, the story of Jōichirō Saiba, it showcases how Jōichirō became The Greatest Hero Karna.