This is a follow-up of the former articles "Writing japanese with Ubuntu 12.04 Precise Pangolin" and "Writing japanese with Ubuntu 10.04 Lucid Lynx".

If you are using Ubuntu 16.04, you can use my respective guide Writing Japanese with Ubuntu 16.04 LTS Xenial Xerus.

When comparing to Ubuntu 12.04, the Japanese input is now a lot easier to install and better integrated into the interface. Additionally you now have the choice between two input methods. I will guide you through both and you can then choose for yourself which you like more.

But first things first for people who haven't typed Japanese in Linux before: The input-methods that are available in Ubuntu 14.04 are Anthy and Mozc. There are others but those are practically the standard ones today and work very well while having all the features you will probably ever need. Anthy has been around for several years and is used as the default in Japanese installations of Ubuntu. However, nowadays there is also Mozc around, which is besically the open-source-version of Google's IME and is in my personal opinion superior because from my experience it gives better results in the candidates list and also has symbols built-in (e.g. ☎). First I will show you the installation and setup of Anthy and after that how to install Mozc.

Anthy

1. Because Anthy is not installed with the base-system, you have to install the Japanese language support first. Otherwise Anthy won't be available as input-method in the Text Entry settings. Additionally this will install some nice Japanese fonts and Japanese translations for Ubuntu if you ever want to use your System in Japanese. So let's begin by opening the System Settings and then the Language Support.
   
2. In the Language Support-window, click on "Install / Remove Languages...".
   
3. Scroll down or type "J" and check the checkbox next to Japanese in the "Installed"-column. After this, click on "Apply Changes".
   
4. Next you have to enter your password.
   
5. The necessary packages will now be downloaded and installed. Nothingto do in this step. :-)
   
6. After the Japanese language support is installed, you have to logout. For Anthy to show up in the list of input-methods, the session needs to be restarted. This is really kind of annoying but there's nothing you can do about that at this point. :-(
7. Once you did a logout / login-cycle, reopen the System Settings and this time click on Text Entry.
   
8. In the "Text Entry"-window, click on the small Plus-sign at the bottom of "Input sources to use".
   
9. Select the entry "Japanese (Anthy)" from the list and click on "Add".
   
10. "Japanese (Anthy)" should now show up inside the "Text Entry"-window and Anthy should be available in menu-bar's menu. You probably want to change the setting "Use the same source for all windows" to "Allow different sources for each window" and switch to "New windows use the default source". Also you want to reassign the key to switch to the next input source eventually. I normally use the "Pause"-key to toggle between languages.
    
    
11. Now fire up some text-editor and try it by clicking on "Anthy" in the menu bar and type some japanese. Switching between candidates is done by pressing the spacebar and katakana-conversion is done by pressing F7.
    

That's it for Anthy. If you want to add Symbols (e.g. the aforementioned ☎) and want to know more about Anthy, you can head over to my article "Some Secrets of IBus / Anthy".
OK, next is Mozc.

Mozc

1. To install Mozc, you have to open a terminal by pressing Ctrl+Alt+T and enter "sudo apt-get -y install ibus-mozc".

   moritz@master:~$ sudo apt-get -y install ibus-mozc

2. After you installed the package, you have to logout. Otherwise Mozc won't show up in the available input-sources.
3. Once you did a logout / login-cycle, open the System Settings and click on Text Entry.
   
4. In the "Text Entry"-window, click on the small Plus-sign at the bottom of "Input sources to use".
   
5. Select the entry "Japanese (Mozc)" from the list and click on "Add".
   
6. "Japanese (Mozc)" should now show up inside the "Text Entry"-window and Mozc should be available in menu-bar's menu. You probably want to change the setting "Use the same source for all windows" to "Allow different sources for each window" and switch to "New windows use the default source". Also you want to reassign the key to switch to the next input source eventually. I normally use the "Pause"-key to toggle between languages.
   
   
7. Now fire up some text-editor and try it by clicking on "Mozc" in the menu bar and type some japanese. Switching between candidates is done by pressing the spacebar and katakana-conversion is done by pressing F7.
   

I hope, this article answered all your first questions regarding Japanese input in Ubuntu.

If this article was useful to you, you might also be interested in my (short) list of extremely useful Japanese software and websites and how to type specific symbols and radicals in Mocz / Google’s Japanese IME.