Zhang Li Hua, the actress who plays grandma Nai Nai, is director Sean Wang's real-life grandmother. She had previously co-starred in Wang's Academy Award-nominated documentary short Nai Nai & Wài Pó (2023).
Pertaining to the title of this film, "Dìdi" means "younger brother" in Mandarin Chinese.
When Dìdi mentions he makes videos, his mother Chungsing refers to him as her "little Ang Lee". Joan Chen, the actress who plays Chungsing, costarred in Lujuria y traición (2007), which Lee directed.
Spike Jonze: As the voice of the dead squirrel during Chris' hallucination. Earlier in the film, one of the skater boys jokes that Chris will be the next Spike Jonze.
Stephanie Hsu: As the Kissing Tutorial Instructor whose video Izaac Wang's character looks up on Google. Hsu's name can also be seen on the Visual Arts sign up list later on in the film.