Trivia: Charlie singing karaoke with Matsumoto was a last-minute addition to the film conceived by Andy Garcia. Garcia felt that the scene would not only be fun, but help the audience connect more with his character Charlie, which would then make his death in the following scene even more shocking.
Trivia: A great deal of the film was actually shot in Japan, and it was reportedly very difficult on the cast and crew. The cost to film in Japan was very high, and the shoot was highly restricted, causing frequent issues. The original cinematographer even left production because he became too frustrated by the experience. Filming was eventually moved to the US to combat these issues.