If you have Japanese files and/or directories on your Mac OS X filesystem, BC will not work with them out of the box. Run CrossOver from the command line thusly:
$ LC_CTYPE=ja_JP.UTF-8 open -a CrossOver
CrossOver will then switch fonts around so that one may successfully use Japanese in the file and directory names.
One may perform comparisons within BC by adjusting the font settings in Options and following the directions in the ScooterSoftware knowledge base here:
http://www.scootersoftware.com/support.php?c=kb_unicodeandcharactersets.php