A magical school needs magical teachers.
But since the game is mostly about interacting with your classmates, it is a Two Teacher School. (Helpful handwave - there are other teachers dealing with the students who aren't freshmen, you're a freshman, so you don't see them.)
In this corner, we have the perky Professor Potsdam.
And in this corner, we have the grumpy Professor Grabiner.
He's... not so colorful.
Of course, I could be completely lying with those links. Never trust marketing!