The LibreOffice project is an aimed at multilingualism, as stated in The Document Foundation's "Our Values" of "Our Next Decade Manifesto" that anyone can translate so that everyone can use it in their mother tongue. However, LibreOffice developers are mostly in Europe, and in order to use them conveniently in other languages, those who understand those languages ​​need to solve the problem. LibreOffice 's CJK and problems unique to the Japanese environment are various such as vertical writing, external characters, phonetic, currency and date notation. Sometimes CJK regression bugs occur in the LibreOffice project. It is important to strengthen user's feedback loop approach. It is also important how to test. In last year's openSUSE.Asia 2018 talk, I organized mainly examples of concrete CJK bugs. In this year's talk, As the first, I will introduce typical CJK bugs. Secondly, I will consider the background of the issues. Thirdly, I will think about how to testing CJK bugs.