While the story of Mulan is not directly based on the Chinese folktale "Yeh-Shen," the original story, written by screenwriter Rita Hsiao, drew heavily from its themes of a strong female protagonist defying societal expectations to save her family and country. The "Yeh-Shen" story, also known as "The Chinese Cinderella," is a popular Chinese folktale about a young woman mistreated by her stepmother and stepsisters who is aided by a magical fish.
While the Disney movie "Mulan" eventually diverged from the "Yeh-Shen" story, its early development was influenced by it.