OK, I certainly understand the problem. Q2A converts text into words (for searching) based on separating out words by word delimiters, like spaces (obviously), commas, quote marks, etc...
You can see the full set used at the top of qa-util-string.php, in the constant QA_PREG_INDEX_WORD_SEPARATOR and also in the mapping $qa_utf8punctuation which converts UTF-8 punctuation characters.
In the case of Chinese and similar languages, there are no word delimiters per se, but rather each multibyte (UTF-8) character is essentially a separate word.
So the solution is to modify function qa_string_to_words() in qa-util-string.php to identify UTF-8 characters in Chinese and similar languages, and split them into separate words as well. One simple way would be to do something at the start of the function that inserts a space before and after each Chinese character, which will then be detected later as a word separator.
Assuming you get this to work, it would be great if you would post your code.
Also, don't forget to click the 'Reindex' button in the 'Stats' section of the 'Admin' panel to make sure all the content is reindexed correctly.