Plenty of Japanese films feature foreigners, from extras in club scenes to main characters, such as Iain Glen's title hero in Masahiro Shinoda's WWII thriller "Spy Sorge" or Bae Doona's Korean exchange student in Nobuhiro Yamashita's high school comedy "Linda, Linda, Linda."
Whatever the size of the role, the foreign character is usually a visitor or an intruder in an otherwise Japanese world. The film's emotional center of gravity — that is, the character the audience is invited to identify with — is nearly always a local.
Kazuaki Ue's "Darling wa Gaikokujin" (My Darling Is a Foreigner) is no exception.