The number 4 is considered unlucky in Chinese culture; it sounds similar to the word for "death" in both Mandarin and Cantonese.
The temple was inspired by the Bok Kai Temple, a historical landmark in Marysville, California that was built by the local Chinese community in 1880. A special thanks is made in the credits.
The family's nickname for Meilin, "mei-mei," is Mandarin for "little sister."
Pete Docter basically described Mei's situation in the movie as "the Hulk, but cuter" when presenting it at the D23 Presentation 2021.
In interviews, director Domee Shi said the film was inspired by four Japanese anime: Fruits Basket (2001), Ranma ½ (1989), Sailor Moon (1992), and Inuyasha (2000). The first two share themes of adolescence and transformations in wacky situations.