There's only one Magistrate. The system is new for the year the game takes place in, so previously the now second year students would have faced higher fees (Lowered now, due to the GATDAM system)
Admittedly, I just made that up. I hadn't really thought about the financial situation of the second year students. They're intended mostly as background characters so the academy has more than 7 girls in it. They may have some scenes, but I'm not 100% sure yet.