What's this korean horror movie?

ive seen a korean horror movie(which i wasn't able to finish)in a bus from the province to a city and when i ride it was already starting. it's about a school of girls and the school's principal is very strict. the school is for idiots where if the students didn't p they'r not able to get to college. there is this new girl where she always break rules and really hates her mom for putting her in that school. she discovered a room full of ghosts where this room, as told by the students, was burned by the school officials together with the students. the new girl always see ghosts crying for help until she became paranoid. .. that's all i was able to watch. ireally want to know the title of this korean horror movie..i don't think that its the "whispering corridors" because the girls in the school have dark clrooms and they wear like p.e. uniforms and they live in that school. the settings is really dark and the new girl is named like eu-jin (i'm not really sure). pls help me.