The Demon Lord is a Child!?

Xcta Demio became a demon lord at age of twelve. Xcta's father is peace loving, so he went all over the continent making peace treaty between demons and humans. Unfortunately, he was assassinated on his five of fifty meetings. The death of the demon lord uproar the entire demons. They are getting ready for war. Xcta never like wars. He came up with an idea that he will attend a human school. Arfoun Shuo Piyaz Academy, the number one prestigeous school of the world. Which won't turn out very well. In order to keep the 8th Purge from happening, Xcta musn't be left astray. He can't be alone due to other demons fear of another demon lord dying, so he chose his number one maid Dest Yer who guide the previous demon lord him will tend to his health. The real fun starts here, Xcta is really knowledgeable, but he doesn't know how to fight nor know how to use to magic. Later on, he uses magic without noticing.