 Wu had previously lived in Los Angeles, and he based the character of Mishalli on Jerry Moses, a Jewish American friend who was originally from Breslau (now Wrocław, Poland) who, like the characters of Rina and Mishalli, was offered a safe haven in Shanghai.Moses and other Jewish friends helped Wu to learn about Jewish religious practices.Wu has stated that his main reason for making the film was to let children know about what really happened, and to promote the story and the history so that people all over the world can learn from it.