It's about girl who is brought in some kind of dormitory. I don't remember about the reason why she was brought there :/ in the dormitory the girls which were already there at first didn't liked her, after a while they have changed their mind and helped her to make some changes (made her hair from curly to straight, used some make up... made her more beautiful)... she was some kind of nerd so she helped them to win some kind of competition. If I remember quite well it was a musical. Thanks for help

Sounds like st trinians