Rainbow Across the Pacific Ocean (1992)

Schoolgirl Mitsuko tries to protect half-Chinese transfer student Yu-Lian from bullies. That night, she discovers Emily, an old American doll. Given to a Japanese child during an exchange in 1921, it was hidden from the "doll burnings" of the anti-Western war period and saved by a brave young girl (Mitsuko's grandmother). At the next day's show-and-tell, Mitsuko tells the story of Emily and encourages Yu-Lian.

Unfortunately the movie Rainbow Across the Pacific Ocean is not yet available on HBO Max.