Hi Peacefreak
The Japanese looks fine to me. But the search ... not so good.
I can get results for text expressed in latin characters, DVD for example, and 911 generates more results in Japanese than in English. However, to do this I need to enter them using an English input method. If I use a Japanese input method DVD's OK but unless I use half width alphanumeric, 911 no longer matches up to the western encoding and I get no results. Hiragana / Katakana - nothing. One surprising result, 本 actually returned a hit, but I think that this was a random result where the search routines interpretatio n of the two bytes making up 本 just happened to match something else. Certainly there were no references to 本 on page that was returned.
My guess is that the search algorithm cannot cope with multibyte characters. Even if it could, if it's based on MySQL, it may need your page format to the UTF rather than EUC-JP. As you can probably tell, I'm now bumping up against the limts of my knowledge in this area, so hopefully somebody more knowledgeable will step in and take this further. It would help to know which Zen Cart version you are using (is it one of the Japanese releases and if so which one?) and which version of MySQL you are using.