Well, I tend to avoid villains if possible, but I could incorporate some as characters.
I also had this weird idea of having Jagen himself be a Janitor or somesuch. Older characters could be featured as teachers, as well as Jeigan units being part of staff.
Cecilia might not teach magic, cause... well, it's a real world setting, but I think she can teach math if possible. I'll figure out just what to do with these characters in time.
The subjects will be the kind of stuff they teach in real Japan high schools, which can include Japanese, English, home economics, Calligraphy, among other things.
I dunno about crazy love, but some students will have feeling for others in the story, I guess.
Yes, there will be normal students and teachers, but I might not feature them too much, unless I need a normal character.
As for the violent characters... eh, I dunno. I'd imagine characters like that to be like others, except they might have a lot of urges to do violent stuff.