Being a part of the Kowai Dōwa (コワイ童話, Scary Fairy Tales) series, the movie stars Chiaki Kuriyama.
Saeko Machida is a 16-year-old studious high-school girl who has a crush on a boy in her class named Yuichi Kimijima.
One day, she meets a strange man at a flea-market who gives her a red liquid, telling her that if she splashes it on Yuichi, her wish will become true.
Later on, Saeko starts to have a new look following Yuichi's disappearance, causing Misa, a rough, tomboyish female and her friends at her school to grow suspicious of her.
She stealthy follows her and hides in the stall next to Saeko in the bathroom and witnesses her with Yuichi tied up on her cell phone and threatens to flush him away if he's going to run away again.
While trying to outrun her, Saeko caught Aya and spills the red liquid in order to prevent her from telling everyone about what happened to Yuichi.
Saeko is forced to stop before railroad crossing barricade and sees Yuichi running away at the opposite end before he stops next to the feet of a female pedestrian wearing an oversized wide-legged jeans and straw platform sandals easily dwarfing him as he drops one final smug back at Saeko before fleeing.
Seako tries to take a better look from afar but a train passes in front of her, letting Yuichi have enough time to disappear into the streets.
The furious Saeko catches Aya attempting to escape while hiding inside a paper-made Sumo wrestler and crushes her to death under her slipper.
During his time in the tiny colony, Yuichi discovers that the men has chosen to shrink themselves about three inches tall for any reason they have which includes avoiding trouble with the law.
Even her disbelieving classmates rally to Misa's side by claiming that she had a suspicious and devious smile when she threatened to shrink them too.
While sitting on the stairs near the tunnel, she cries out for Yuichi's help to save her from being arrested and finds a small man attempting to tie her shoe laces together.
Alone and depressed, Saeko attempts suicide by throwing herself off the bridge into the road below, but is saved by the flea-market man who just happened to be nearby.
As part of her guilt, Saeko asks for the flea-market man for one last favor by letting her switch places with Yuichi since she should've been a lot happier watching him from afar rather than continuing to be lovesick over him.
The man takes the sleeping Yuichi to the park bench and uses the blue liquid and grows him back to his normal size.
In the real ending, a subsequent scene reveals Saeko inside a bird cage after being turned in to the authorities by Yuichi, who observes on the TV screen by the front window display of the shop.
The reporters surround Saeko's cage wanting answers from her in why she'd killed Aya and held Yuichi hostage for so long.