A young man who was left abandoned on a doorstep as an infant due to his tragic fate, which he didn't learn about it until he grew up and went to attend Constant Magic Academy. Yes, Sai Akuto is going to become... the demon king.
Once upon a time, a little baby named Akuto was left at the doorstep of a church. Several years later, that boy grew into a young man who was inspired by the church to become a great priest (like the Pope), and he decided to head off to Constantin Magical Academy to hone his magical gifts so that he could use them for the good of mankind.
However, when he went in front of the vocational raven to divine his future, the raven proclaimed that Akuto was destined to become the next Maou, or Demon King, a being so evil and so powerful that he nearly destroyed the world.
Akuto has spent most of his time trying to convince his fellow classmates that he won't turn into an evil person, but events just keep conspiring against Akuto to dig that hole deeper. Whether he's being attacked by a fellow student, manipulated by an evil lady, or simply watching as his magic turns a class project into something wrong, Akuto just can't seem to catch a break. Even so, he slowly builds up a posse of followers ranging from a young fanboy to a robotic private detective who all have their own reasons for wanting to see whether or not Akuto will become the future Maou.
In Japanese, Sai Akuto (最悪人) can be interpreted as "the worst person" in English.