1. System Settings -> Locale -> System Languages -> Download Language support -> wait for download to complete
2. Install Tab -> Japanese -> Download Language Support -> Wait for Download to complete -> Do not close this window
3. Synaptic Package Manager -> mark for downloads: Ibus Anthy, Mecab & Kasumi -> Apply -> Close after changes applied
4. Applications -> Settings -> Keyboard Input Methods -> Click "Yes" to start ibus daemon -> close
5. Go back to the System Language Window from Step 2 above -> Set System Language Tab -> Select Japanese Language -> go to the drop-down box at the bottom right and select ibus -> Click Apply -> click OK when Alert box says the default system language is Japanese -> your original default system language and click apply. (We don't want our system language to be Japanese, we only want Japanese support.)
6. Click Country/Region & Language on the left -> Move the desired language to the right from the left with Japanese now being an option -> click Apply and OK for the Alert Box. -> wait for it to update
7. Click on Overview at the top to go back to the main systems settings -> Click on "Startup and Shutdown" at System Administration on the bottom -> click "Add Program" -> Type "ibus" in the text box and select "ibus-daemon" -> Click OK -> Click Application Tab -> Type in the following text box: Name: "Ibus", Description: "Japanese IME", Command: "ibus-daemon -d" -> click OK (This will start-up Ibus everytime the system boot up). -> Close System Settings Window.
8. Shutdown -> Restart
9. Applications -> Settings -> Keyboard Input Methods -> Input Method Tab -> Click on the "Select and Input Method" drop-down box -> "> Japanese" will be displayed" with Japanese greyed-out. -> Do not click on "Japanese" but click on the ">" before it. -> "Anthy" will appear -> Select "Anthy" -> Click "Add" -> "Japanese Anthy" will appear in the text area. -> close.
10. Shutdown -> Restart
11. Test with several input windows such as "kate", "mozilla" & "LibreOffice Writer". It had only worked for "kate" before the shutdown/restart in step 10 above. (CTR+space to switch between languages)