My objective is to be able to switch between English and Japanese input at will from the same keyboard.
I have tried every guide I can find and almost every one says the same thing or references software that isn't packaged with Ubuntu.
Settings > Region & Language > Manage Installed Languages... So on and so forth.

I can switch between languages using Super + space, but when I check the visual keyboard layout nearly everything is the same. Changing between "languages" only alters some punctuation keys. Every letter key remains the same. Not a single Japanese character can be found. What gives?