I could totally see this series going the harem route with the girls. Of course, you can't add about a billion more as it would just be too much, but the main ones and StuCo prez being added would make sense.
We've been seeing in more recent chapters how all of the girls are getting along somewhat well now. Sure they hate that one of them gets ahead of any of the others, but that makes sense currently. As it stands the girls are starting to accept each other as not just rivals in love for a guy who really doesn't have anything else on his mind but fashion, but also as "friends" so this could become a harem with the core girls.