At the Unicode Conference in Santa Clara, California, where the Maps Transliteration team is giving a talk about ICU-based transliteration. “Transliterating this originally Spanish city name to Japanese, we get ???????, which (when morphed back to the Latin writing system) becomes “Santa Kurara”.”
The Maps team “contributed ICU transliteration rules for Czech, Italian, Japanese, Korean, Mandarin, Polish, Romanian, Russian, Slovak and Spanish to the Unicode Common Locale Data Repository. For languages with very irregular spelling, like English, we supplement ICU with some more advanced techniques,” informed Google.
If you would like to try writing rules for your own language, have a look at the instructions in the ICU user guide.