I know this has been asked before, but I haven't seen any new information regarding the adding of Japanese characters.
There is clearly a desire, as many people have asked, but I don't know what progress, if any, has been made toward adding them.
Aside from the Kanji (漢字) characters, there are relatively few Hiragana and Katakana characters. I don't expect the Videoscribe team to add any of the Kanji characters, but I would think it would be quite simple to add both Hiragana and Katakana characters.
I am already familiar with how to get Videosribe to draw Japanese (and other) characters, but it is quite troublesome/time consuming.