What's happening is I'm trying to play back a MKV file with a Japanese UTF-8 encoded A*S (won't let me type the extension) subtitle file muxed in. Some of the characters appear correctly, while some appear as square and the hiragana/katakana appear to be in a different (somehow monospaced) font than the kanji:
![Image](http://files.droplr.com/files/15377774/jRNY.Screen%20shot%202010-11-15%20at%202.55.11%20PM.png)
The text appears properly in Mplayer Extended for OS X, but the subtitles are squished and stretched in a way that makes them difficult to read, which is why I would prefer to use VLC.