Watamote: I watched disc 1 (4 episodes), can see what you meant by saying Monica nails this role.
I think it's cause she was like that in school.
If you have seen older pictures/videos of her, you know she was a large girl.
With possibly Goth tendencies, so I would guess she wasn't "popular".
Anyhow that's just a guess.
This show is pretty fun.
Though the opening theme is rather odd.