Furiganize is furigana (Japanese phonetic symbols) insertion macro for LibreOffice
(should work in OpenOffice too, but I did not check)
It is written in Python and uses mecab and kakasi installed system-wide
It makes things easier for Linux users, you just need to install kakasi, mecab and mecab-naist-jdic-eucjp packages,
they are usually available form standard repositories.
Then copy macro to your LibreOffice script path,
something like ~/.config/libreoffice/4/user/Scripts/python
(libreoffice-script-provider-python package should be installed to enable Python macros in LibreOffice)
select you Japanese text and run macro.
In case of Windows it might be a little bit more complicated,
you also need to install mecab and kakasi and make sure they are included in %PATH%.
The other option is to put executables and dictionary files alongside with the macro
and change couple of line in it to indicate where the files are.
Please contact me if you are in trouble.
Enjoy :)
p.s.
Suggested reading might not always be 100% correct, but it's more due to the limitations of mecab, rather than the macro.
Furigana is inserted as "ruby text", to edit it go to main menu -> Format -> Asian phonetic guide