Chapter 1 of Tomie, and the first story ever to feature Tomie.
Tomie Kawakami was murdered on her way back from a school trip. Her body was found in dozens of pieces and the killer hasn't been caught. However, Tomie returns to school as if nothing happened. Her teacher, Mr. Takagi, tries to ask her what happened. He thinks she must be Tomie's twin, but she denies this and tells him she loves him. Takagi has a nervous breakdown.
Although Tomie had been positively identified by dental records, the pieces collected by the crime lab have now been cremated, so they can't check again. Yamamoto, who had been Tomie's boyfriend, is disturbed by the events and wants nothing to do with her. Tomie tries to ask her friend Reiko why people are treating her differently but Reiko can't answer. Tomie jumps off a bridge and disappears, causing Reiko to wonder if Tomie was a ghost all along. Reiko catches up with Yamamoto, who thinks that Tomie came to drive them crazy. He believes Tomie will torment them until they give themselves up to the police.
A flashback shows that when the class went on their field trip to a mountain, Yamamoto caught Tomie cheating on him with Mr. Takagi. They had an argument that caused Tomie to fall over the mountainside to her death. Yamamoto wanted to go to the police but the whole class, except Reiko, hated Tomie and told him not to throw away his life for her. They cut her into pieces and gave one to each member of the class, with each person responsible for disposing of it. Reiko, as Tomie's only female friend, was given her heart and dropped it into the river - at the spot on the bridge where Reiko has just seen Tomie jump.
The others in the class discover that Yamamoto and Reiko are planning to go to the police. They corner the two and try to kill them but are interrupted by the arrival of Tomie. Yamamoto and Reiko are left alone with her, and she asks if Reiko has been seeing Yamamoto behind Tomie's back. Reiko manages to run away. She explains that Yamamoto was later found but had been driven insane. Several of her classmates have dropped out of school or committed suicide, while Reiko's family moved to the seaside. She is still not sure what happened, and wonders if Tomie's death on the school trip was some kind of mass hallucination.
The story ends as Reiko discovers that Tomie's heart washed up in the sea and is regenerating into a new Tomie.