what is the movie spirited away based on
It is based on the10-year-old daughter of Seiji Okuda
Spirited Away
Miyazaki wrote the script after he decided the film would be based on the 10-year-old daughter of his friend Seiji Okuda, the movie's associate producer, who came to visit his house each summer. 
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Spirited Away [SEP] Introduction
Miyazaki wrote the script after he decided the film would be based on the 10-year-old daughter of his friend Seiji Okuda, the movie's associate producer, who came to visit his house each summer. At the time, Miyazaki was developing two personal projects, but they were rejected. With a budget of US$19 million, production of "Spirited Away" began in 2000. Pixar animator John Lasseter, a fan and friend of Miyazaki, convinced Walt Disney Pictures to buy the film's North American distribution rights, and served as executive producer of its English-dubbed version. Lasseter then hired Kirk Wise as director and Donald W.