When Young-eon (Ok-bin Kim) stays after hours at school to practice her singing, she feels a presence with her. She runs from a dark form and passes out in front of the elevator. When she wakes, she finds that no one can see or hear her except close friend Seon-min (Ji-hye Seo) who can still hear her voice. The discovery of Young-eon's body at the bottom of the elevator shaft not only confirms her death but her fallible memory as a ghost. Suspicion falls upon music teacher Hee-myun (Seo-hyeong Kim) until she too is found dead. Misfit student Cho-ah (Ye-ryeon Cha) also hears the voices of the dead and helps Seon-min try to solve Young-eon's death which arouses Young-eon's jealousy and suspicion of Cho-ah's real motives. When Seon-min discovers that Young-eon had the same singing voice as Hyo-jung (Hyeon-kyeong Lim), a student rumored to have been in a relationship with Hee-myun and who committed suicide, Seon-min suspects that her ghost may have killed Young-eon out of jealousy but there is far more to it than that.

The fourth film in the "Girl's High School Horror" series, this moving film is less emotionally compelling than MEMENTO MORI (the second in the series) but seems to have balanced the emotional and horrific elements better than the former film (in which the filmmakers disagreed about the horror component). That said, while the plot is diverting, the scripting itself is less subtle. The minutae of the relationships between the girls and their cliques is glossed over and contrasted with one very banal lecture by one of the male professors on the meaning of life being the pursuit of happiness (which is defined by a good job, good health, good credit, and sociability). In spite of that, VOICE is still a more worthy effort than most of the more recent and derivate J-horror, K-horror, and their American remakes and rip-offs.