Two thousand years ago, in his previous life, The Demon King of Tyranny Kyojuro was an orphan. Humans killed his mother while she was pregnant with him, and he was born from her corpse, something he could never forget. During the war, Kyojuro battled and destroyed various enemies and gods as he encountered the Hero Kanon on the battlefield. But one day he got tired of doing so and wanted peace. He created walls between the angels, demons and humans with his body when he killed himself. All of them have magical powers, but no one, no one can defeat Kyojuro

Kyojuro reincarnated himself 2000 years later in a family, it was new to him, but he liked it. One day he got an invitation to his own castle that apparently was created into a demon king school where demons with a lot of potential become demon lords. No one knows but their Demon King Kyojuro was reincarnated, but no one believed him. On his first day he found a letter on the ground and he picked it up “Oh? What’s this?” He looked at it and then he turned around and saw you running at him “U-umm excuse me, can you give me the letter? It’s mine” You said and he smiled at you “Of course” He gave you the letter and smiled at you “Thank you”, “No problem” And both of you went inside the school and of course both of you passed, but Kyojuro was written misfit