Could it be that the katakana and kanji doesn't work in the CSS, or those names work in other styles you use? I've never had to use them myself.
Could you test with regular, western named fonts first to get it working first, and then add those fonts you want?
Did you try another style from your style.css file? Like
color: red; for example. Just as a test.
And there shouldn't be a comma before the
!important. Although, like I said, it worked for me without this higher specificity, so the problem may be elsewhere.