PDF report only print an initial letter in Japanese version

I using Piwik 3.2.0 in Japanese version, and unifont.ttf uploaded to piwik/plugins/ImageGraph/fonts/ in web server(cf. 24. PDF/HTML レポートのグラフと Piwik モバイルグラフで unicode 文字 (日本語、中国語、ロシア語、ヘブライ語、アラビア語など) を有効にするには ? | 日本Piwikユーザー会).
So, letter is printed correctly in graphs.

But some items printed only an initial letter in downloaded report(ex. two items printed only “RE” in red rectangle, perhaps it means “repeater something something …” in below image.).

How do I resolve to?