some trivia about the Japanese guy in Fearless (Jet Li's last action movie)
"Shido Nakamura does not speak Mandarin, but he needed to in the film, so he found a tutor, even though the director told him to just memorize and recite the sounds. He also tried watching TV channels in Shanghai, but it wasn't a week later until one of the film crew noticed that he was watching a Cantonese channel, which of course, speaks Cantonese, not Mandarin." - IMDB