I installed the WP-Postview plugin for WordPress. Everything was fine until it encountered Japanese. Then it barfed repeatedly with “Warning: Cannot yet handle MBCS in html_entity_decode()!”.
To work around this problem, I found some great notes on SearchMarked.com.
Edit the wp-postviews.php file, replacing
$text = html_entity_decode($text, ENT_QUOTES, get_option('blog_charset'));
with
$text = utf8_decode($text);