Whispering Corridor 4: The Voice (2005)

Young Eon, an innocent girl-next-door type who has a remarkable talent for singing. When her best friend Sun Min shows up at the music room, Young Eon has to decline her offer to hang out because she wants to continue practicing. Of course, spooky things start to happen when Young Eon is left alone in the school, a fact which culminates in our heroine getting killed in a gruesome, yet slightly hilarious way - death by paper cut. Or is that actually what happens?