A young woman named Kazue runs over a naked girl on a mountain road. When she stops to help, the girl runs off into an old abandoned house in the middle of the woods.

Within days after the mysterious new student Kawakami Tomie joins a high school classroom, all hell literally breaks loose. Simple in-fighting between boys and girls over Tomie's oppressive shadow soon gives way to mind-breaking violence, culminating in a grizzly dissection that ultimately leads to suicide, insanity, and even more violence.

Following some trauma in her past that has since been repressed, a young woman is trying to recover her memories with the help of a psychiatrist. During her hypnosis sessions, she repeats the name "Tomie" but is unable to recall where she knows it from. Meanwhile, a police detective is investigating a string of brutal murders, where he also runs across the name "Tomie." How are the two connected?

While celebrating with her friends in her new cheaply rented apartment on the thirteenth floor of a building, the young Sayaka unexpectedly jumps off the balcony committing suicide. Her mother goes insane and her older sister, Mariko, decides to investigate the mysterious death of her sister.