I suppose that you just installed kubuntu 11.10 in your box, and english is your default system language.
- Install the following packages: ibus, ibus-anthy, ibus-gtk, ibus-m17n
- Go to the “K” menu -> applications -> system -> input setting framework
- A box will show up with the ibus configuration options (and maybe asking you if it should start ibus, say yes)
- configure your desired shortcuts in the “general” tab. Make sure to configure keys for “enable-disable” and “next input method”. In the “input methods” tab, add “Japanese->anthy” and “other->latin pre”
- Close the configuration screen. Right-click on the ibus icon in your tray bar (a little keyboard with a ball) and select “restart” — you are good to go!
I always had difficulty getting both japanese and portuguese to work in my systems, it has become so easy now! How far have we come :-)