In order to animate the scene where Chihiro force feeds Haku the medicine in his dragon form, Hayao Miyazaki had his animators study a dog's mouth as they fed it treats while a veterinarian held its lower jaw.
To do the voice of Chihiro's mother talking while eating, actress Yasuko Sawaguchi actually spoke the dialog (in the original Japanese-language version) while eating a piece of Kentucky Fried Chicken. Actress Lauren Holly did the same thing in the English version with an apple.
In the scene during which Chihiro squashes the small worm like thing that inhabited Haku with her foot that, Kamaji tells Chihiro to "Cut the line!" Cutting the line is a Japanese good-luck charm performed by making a chopping gesture through another person's connected index fingers. This is done whenever someone is affected by some impurity. During footage of the dubbing process in the "Spirited Away" Nippon-TV Special, Rumi Hiiragi, playing Chihiro, was not aware of this concept and had it explained to her by Hayao Miyazaki. One of the sound engineers commented, "The young don't know it these days."
The song over the closing credits ("Itsumo Nando Demo"/"Always With Me") was intended for a Hayao Miyazaki film that was never made. Miyazaki played it relentlessly while making this film and decided to include it in the end credits.
Chihiro's father drives a first-generation Audi A4 sedan. The level of detail included by the director includes the Audi's trademark "Quattro" four-wheel drive system when Chihiro's father decides to take the car in the forest, along with the ABS (anti-lock brake system), which pushes the brake pedal back when Chihiro's father brakes hard seeing the statue.
Despite having a rich plot with developed characters, Spirited Away (2001) was not made with a script. In fact, Miyazaki's films never had scripts. "I don't have the story finished and ready when we start work on a film," the filmmaker told Midnight Eye. "I usually don't have the time. So the story develops when I start drawing storyboards. The production starts very soon thereafter, while the storyboards are still developing." Miyazaki does not know where the plot is going, and he lets it happen organically. "It's not me who makes the film. The film makes itself and I have no choice but to follow".
The theme of not looking back is an homage to the Shinto Myth of Izanagi (& Izanami) escaping from the Underground World of Death (Yomino Kuni), which is very similar to the Greek myth of Orpheus and Eurydice. Many of the characters in this animation are based on Shinto Myth and have Shinto Gods' names. For example, Haku's true name 'Nigihayami Kohakunushi' is taken from an actual God's name Nigihayahi.
Executive Producer John Lasseter of Pixar supervised the English-language dubbing of the film and tried to match the actors' English-language dialog with the mouth movements of the animated characters.
The city that Chihiro and her parents are moving to at the beginning is the fictional city of Tochinoki along Route 21, just north of Nagoya. Tochinoki is also the name of an amusement park to the north of Tôkyô and a spa resort in the south of Japan. The large hill in their neighborhood where the dirt road begins is named Green Hill.
The characters in Spirited Away (2001) reflect who they are. "Boh" means little boy or son, "Kamaji" means old boiler man, "Yubaba" means bathhouse witch, and "Zeniba" means money witch. The heroine "Chihiro" means a thousand fathoms or searches, while her worker name, "Sen" just means thousand.
There are several instances in the English-dubbed version where dialogue was added in that was not present in the original Japanese release. In an interview with John Lasseter, he explained that it was a necessary addition to help clarify certain elements for American audiences. For example, what is clearly a bathhouse to a Japanese viewer might not be apparent to an American viewer, so this translation issue was fixed by having the character explain, "Oh, it's a bathhouse."
There is a common misconception that the film takes place in brothel. This is false; Miyuzaki made this film targeted towards the demographic of young females. Another quote of the creator that disproves this claim states he is displeased with how the sex industry has become more geared to include children.
In the English-language version, John Ratzenberger (Aniyaku) completely improvised the ditty he sings when he is extolling the virtues of the rich customer No-Face ("Welcome the rich man, he's hard for you to miss..."). The original script's song was "Welcome the rich man--he's pretty big, you see/so all bow down and get on bended knee."
Hayao Miyazaki wrote, directed, and drew the storyboards for the movie; many directors have claimed that he essentially 'writes his movie with drawings', with films like Spirited Away (2001) being one man's work and vision. The filmmaker is so influential and involved in the production, the New Yorker once called him "the auteur of anime."
After his bath by Chihiro/Sen, the river spirit rewards her with an emetic dumpling. Emetic is actually an ancient substance that induces vomiting and only was used for people who swallowed poison. Or, in this movie's case, greedy desires and manipulative agents from lost spirits.
The trivia items below may give away important plot points.
The character No Face greatly resembles a silkworm, an important animal in Japanese culture. No face seems to have a white face and a mouth below it. Silkworms have markings that look like facial features, and their mouths are below these markings. Silkworms and No Face eat constantly and grow rapidly. At the end of the movie, No Face goes with Sen to visit Zeniba. No Face stays with Zeniba spinning silk.
The kanji names of many of the characters provide clues to their identities: Yubaba (hot-water crone), Zeniba (money crone), Kaonashi (no face), Bô (young boy/child), Kamajii (kettle/boiler pot/old man), Chihiro (thousand fathoms or thousand searches), Sen (thousand (pronunciation of chi kanji when isolated)).
A minor dubbing error causes Haku's name to be slurred. His actual given name in "Sen to Chihiro no kamikakushi" is Kohakunushi Nigihayami, while "Spirited Away" just refers to the Kohaku River, ignoring the rest of his name entirely, and therefore changing the meaning of his name drastically.
Lines were added in the English-language-dubbed version that do not exist in the original version; when Sen says that Haku is a dragon after she sees her parents in the barn, and the last lines between Chihiro and her parents in the car at the end.