Whispering Corridors 5: A Blood Pledge (2009)

Whispering Corridors 5: A Blood Pledge 2009 / 여고괴담5 - 동반자살 2009 / Yeogo Goedam 5: Dongban Jasal

Late one night at a high school chapel, four students make a pact to kill themselves that night. The girls sign the pact with their own blood and pledge that if anybody survives they will be haunted for the rest of their lives. Then only one of the four students, Eon Ju, actually commits suicide by jumping to her death. The next day, rumours fly around their school on the reasons why Eon Ju killed herself. The remaining three girls keep to themselves as they are haunted by their pledge and soon enough the school becomes covered in blood. (Source: AsianWiki)