Japanese, like many other Asian languages, is written using a variety of symbols which are not found in the standard ASCII table. Fortunately, you can include these symbols in LaTeX documents using the CJK package. In ubuntu this can be installed via the sudo apt-get install latex-cjk-japanese command. I’m not sure about Windows, Mac or other *nix distributions – let me know if you’ve worked it out.
Basically, adding the Japanese characters to your LaTeX document is as simple as including the cjk package and wrapping all your text in the CJK environment. You can then mix your Japanese with the rest of the document (English, tables, graphs, etc) without any other configuration.
The word konnichiwa (こんにちは in hiragana) is a formal daytime greeting.
Will create a document with the English and Japanese words mixed together. Too easy.