Here is a few dramas/movies that might suit what you are looking for ^ ^
Crazy Little Thing Called Love - (Thai movie) Unattractive girl is in love with Mr. Popular at school.
Busu to Yajuu - (Japanese drama) This has not been subbed that I know of. Sorry >.< However it can be still found without subs on drama sites (e.g. Dramanice). The story is quite easy to follow, short episodes & the heroine girl is plus size.
High School Debut - (Japanese movie) Heroine is a tomboy that is never had a boyfriend or tried to be girly before. A popular and handsome boy in school helps her to find a boyfriend.
Moon River - (Taiwanese drama) Heroine is a martial artist tomboy, starting at a new elite school from the country. When she arrives, she gets into a fight with the most popular arrogant and pretty boys in school. She then needs to apologise to their leader. The story progresses from there.
I hope that I have helped, and that you enjoy!!