They just appear as boxes.
I have Japanese Windows 7 installed.
I've tried changing "text rendering module" to "Freetype2 font renderer".
I've tried changing encoding to UTF-8 Universal.
I've tried changing encoding to SHIFT-JIS.
I've tried changing the font to a Japanese font.
I don't know what else to try. The subtitles work in literally every other player I've use them with.