Extension:APC doesn't properly generate a statics image in Japanese characters (probably other non-latin characters too). See http://translatewiki.net/wiki/File:ViewAPC.png for example. It is a partial screenshot of Special:ViewAPC (a special page showing APC statics) showing the bottom table titled "Detailed memory usage and fragmentation" ("メモリ使用および断片化の詳細" in Japanese) there. It shows some broken characters after arabic numerals the in statics image. Correctly, they would be "キロバイト" or some other Japanese text. Compare the text message below the image. Please display http://translatewiki.net/wiki/Special:ViewAPC in various language settings.
It will need a sophisticated way for drawing localized texts to images in MediaWiki.