I doubt that the student being forced into signing up would cause enough trouble to get expelled, as I'm very sure that his parents would certainly unleash hell upon him, assuming that he'd know that. That's certainly something that'll get him to cooperate with the program.
Oh, before I forget, how are the students going to know which class they take at the start of each day?
Let's see... how about if the parents of the said potential student winds up being threatened that, if their child doesn't sign up to attend the academy, that the kid will suffer some form of punishment at their parents' hands, physical or otherwise. How does that sound?