Google Developers Blog: Google Fonts launches Japanese support

Posted by the Google Fonts team The Google Fonts catalog now includes Japanese web fonts. Since shipping Korean in February, we have been working to optimize the font slicing system and extend it to support Japanese. The optimization efforts proved fruitful—Korean users now transfer on average over 30% fewer bytes than our previous best solution. This type of on-going optimization is a major goal

[anoncom]

Google Fontで日本語フォントの正式リリースの記事(英語)

[diveintounlimit]

これか

[t-w-o]

Google Fontの日本語対応について(英語)。日本語の特殊要件に対応するため、こんな複雑な対応をしていたんだ……ありがたや。