Didn't one of the antagonists from the school die dealing with Wyverns or the kidnapping attempt? (Maybe it was Rio's first run in with Lucius, I can't recall exactly)
Hiding just in case mlinder's still reading
I can barely remember the other characters from the school, I just happened to be looking that one up recently. Perhaps they might turn up again in the future volumes, as we have to have the Beltrum Princesses pretend that the rest of their school friends hadn't been bullying someone strong enough to easily defeat heroes.