ICU transliterator is fairly sophisticated (and configurable), actually. Take a look at the examples:

  キャンパス -> kyanpasu
  Αλφαβητικός Κατάλογος -> Alphabētikós Katálogos
  биологическом -> biologichyeskom

From: http://userguide.icu-project.org/transforms/general

Edit: reread, OP was talking about Django transliteration, which is much simpler.