Henri Bergius writes "Thanks to Tony Lee, we now have a new translation of Aegir CMS available: Japanese.The translation was added to the development server yesterday. However, installing current Nightly builds is not recommended due to their development status.
The Japanese language pack is also available as a patch from here.
If you want to try it out with your Aegir CMS installation, download the file and install it with:
$ repligard -i aegir-japanese-patch.xml
Aegir CMS is an Open Source Content Management System