what is the name of this Korean movie?

It's diving me crazy! i can remember a few scenes and the main characters faces but no names UGH!!

It's about 2 girls. one a top geeky student and the other is in a gang (you know those groups in school). they are both high school girls. they help each other. the geeky girl wants the hot guy so the bad girl helps her turn bad. in return the geeky girl helps the bad girl raise her grades.

the bad girl is actually tricking the geeky girl because they both like the same guy and the guy told her he only dates smart people like the geeky girl and hates the bad girl type. Over the story they become best friends!

i remember the fight scene:

the bad girl gets turned on by her own gang because she abandon them to hang out with the geeky girl. they start to beat her up in a subway tunnel. the geeky girl gathers scooter fast food driver (like 50) and shows up at the top of the stair case of the subway. the gang runs away and the bad girl is saved.

the last scene is the girls sitting at a table with the boy they like and some other guy (i forgot his role in the story) laughing and having a good time. then the fades out.

hope you can tell me the title by my description :)