http://bugs.winehq.org/show_bug.cgi?id=18349
--- Comment #3 from Michal Suchanek hramrach@centrum.cz 2009-05-05 03:50:12 --- it's specifically this application: http://bugs.winehq.org/attachment.cgi?id=10369 and this patch: http://bugs.winehq.org/attachment.cgi?id=20749
As I understand font linking the Latin characters should not be rendered in the Japanese font in the first place as the System font should have glyphs for ASCII at the very least.
Also I believe the font has consistent glyphs for Latin characters if it came to that.