Romain Grégoire (deviantart doesn't let me put the accent)
My favourite character, no contest.
Brown eyes, brown hair, brown clothes...
Thirty-eight years old, and very strict, he teaches British civilisation. And doesn't understand why some students don't care about it.
I kinda consider him the only grown-up of the lot. All the other characters have some childish features, he doesn't. Of course, as a child, he already didn't.

That could make him boring. But pair him with Margot, his childhood friend, and you'll have some of the funniest parts of the book (in my opinion). It's sometimes hard to believe I added them both as an afterthought.

He has a scar under his left eye and his nose is crooked. Both these marks (and lots of others that can't be seen) were caused by being friends with Margot. And of course, she never got hurt.

He's single, lives alone, no pets. No known family, but I won't say more, because that's an important plot point (Dun Dun Dun).

Oh, and that's his eyebrows regular shape. Doesn't help him look less strict
Also, the dot under his left eyebrow is on purpose, it's a mole.

Not much to add... He's a good guy, deep inside, just doesn't know how to be tender because nobody showed him. Or that's his excuse