you have to have your systems character set set to shift_jis to be able to use japanese in winmx (winmx uses whatever your system is set to), i assume you have it set to that? if not then you need to change it to that (in control panel... also messes up some fonts in things though, nothing you can do about that), if you do then you should be able to use japanese as long as you are not trying to use UTF-8 or any other character set (if you use anything except shift_jis it will fail)