Demon King Daimaou: Volume 1 by Shoutarou Mizuki

Far in the future, Japan has become a land ruled by magic and those who wield it. Akuto Sai arrives at Constant Magical Academy—the most prestigious magic school in the world—for his first year of high school. The only student to pass the Academy’s intense entrance exam, he has his sights set on become a High Priest, the most powerful and virtuous magician in the land. However, when he arrives at the Academy, his future occupation is prophesied to be… The Demon King?! Now Akuto is the number one target on campus, and he must navigate his way with the help of his friends—a troublesome delinquent, a beautiful observer android, an honor-bound class representative, and a mysterious girl from his past—through the seedy underbelly of the world’s premier magic academy.