Ubuntu – Anthy Japanese is using Japanese keyboard layout. How to use US

1. Using Ubuntu Software Center install ibus-anthy. This will give you Japanese keyboard layout.
2. Once you installed iBus, open Dash and look for iBus. Once iBus is running, go to the second tab called Input Method.
3. Make sure "Customize Input Selection Method" is checked. Click on Select and Input Method and select Japanese > anthy. Do not chose "Anthy (m17n)" it does not allow F7, F8 etc. to change fonts Then hit the Add button to add this input method. If Japanese is not at the top, click on it and click Up button to move it to the top. Click on Close button. You will notice a keyboard icon on the top panel in Unity.
4. Now, open a new window of LibreOffice or Gedit or where ever you want to type in Japanese and hit Ctrl+Space. This will change the input method to Anthy for that app. You will notice that the icon on the tray now shows Aち. If you don't see Aち and see the keyboard icon or another language icon on the top panel, click on it and select Japanese-anthy. Now type you can type in Japanese.

Hope this helps

Did you mean Kana input?

ibus-anthy has multiple ways of entering the kana. Default mode is via phonetic romaji (roman alphabets). You can change the input mode to Kana input, which uses the hiragana on the keyboard as you asked.

Since you got ibus-anthy set up, I assume have a toolbar like this floating on your desktop or glued to your panel (source: Ubuntulinux.jp Wiki article on IbusAnthy):

See the third button from the left, with the symbol R. That is the button for selecting input type. R denotes romaji input type. Kana input should be selectable by clicking on that button.

1. You said you chose OADG 109A but the Japanese switch key didn't respond. Does other buttons, say, like the @ key map correctly?
2. I assume by Japanese switch key you mean the one to the left of 1 key, i.e. the Zenkaku_Hankaku key. Di you mean that pressing that key didn't enable Japanese (romaji) input mode? It's possible that your ibus-anthy didn't have Zenkaku_Hankaku as the shortcut to toggle Japanese input. It's configurable via Anthy preferences.