Personality
Chihiro's growth into a capable individual is a core factor to the movement of Spirited Away's plot. During her adventure in the Spirit World, she matures from an easily-scared girl with a child-like personality to match her age to a hard-working, responsible, and brave young girl who has learned to put her fears aside for those she cares for. To protect her friends and rescue her parents from a spell that has turned them into livestock, Chihiro sheds her former personality and adapts to her environment to become a courageous, quick-witted and reliable girl.
The strength of her bond with Haku as the story progresses eventually evolves into a very sincere form of love that dispelled Yubaba and Zeniba's respective curses on Haku.
History
In the beginning of the movie, Chihiro is shown to be a childish, easily-scared and whiny girl. But after her experiences at The Bathhouse, she matures into a capable young adult.
Appearance
Chihiro has brown hair and rosy cheeks. She is very petite and has a childish appearance, and a quite-pudgy face. Her attire includes a white T-shirt with green stripes, pink shorts, white socks and yellowish sneakers. While working in the bath house, she is barefoot and wears a pink and white work uniform with a tasuki cord for tying her sleeves up.
Speculation
It is mentioned by director and creator Hayao Miyazaki that Chihiro has 'lost' all her memories of the Spirit World following her exiting of the tunnel. However, according to Haku's promise, he and Chihiro will meet again someday. This may or may not be referring to Chihiro's eventual death and transformation into a spirit. However, Zeniba's quote, "memories are never forgotten, they are just difficult to recall", suggests that Chihiro could, potentially, remember her experiences at The Bathhouse and the Spirit Realm. Regardless, the fate of Chihiro and Haku's relationship remains unknown and is up to audience interpretation.
Trivia
-In an interview regarding Chihiro's character design, Hayao Miyazaki informs the audience that "[He] created a heroine who is an ordinary girl, someone with whom the audience can sympathize. It's not a story in which the characters grow up, but a story in which they draw on something already inside them, brought out by the particular circumstances. [He] wants [his] young friends to live like that, and [he] thinks they, too, have such a wish."
-Chihiro was created based on a ten-year-old girl, the daughter of a friend of Miyazaki's. This girl also made Miyazaki continue working after promising retirement from filmmaking after Mononoke Hime (1997).
-Chi and Sen both use the same Japanese Kanji, which means '1,000', but are different readings of the same character. The name Sen is also a play on the name Chihiiro.