##  Class files

LaTeX supports many worldwide languages by means of some special packages. In this article is explained how to import and use those packages to create documents in Japanese.

#  Introduction

Japanese language, just as many other oriental languages, requires special fonts and a particular document encoding.

\documentclass{article}

\usepackage{xeCJK}
\setCJKmainfont{AozoraMinchoRegular.ttf}

\begin{document}

\section{これは最初のセクションである}

フォントはまた、数学的な形態および他の環境で使用することができる

\vspace{0.5cm}

And you can also use Latin characters within your Japanese document.

\end{document}

Documents in Japanese are usually formatted with the Japanese LaTeX distribution pLatex. But if you already have a LaTeX installation or want to compile your document on-line with ShareLaTeX you can use the CJK (Chinese, Japanese and Korean) package. Please note that the compiler will have to be set to XeLaTeX for this to work.

#  CJK with XeLaTeX

XƎLaTeX offers the possibility of importing external popular fonts or using the ones you already have in your Operating System:

\documentclass{article}

\usepackage{xeCJK}
\setCJKmainfont{AozoraMinchoRegular.ttf}
\setCJKsansfont{KodomoRounded-Light.otf}
\setCJKmonofont{KodomoRounded-Light.otf}

\begin{document}

\section{これは最初のセクションである}

フォントはまた、数学的な形態および他の環境で使用することができる

\vspace{0.5cm}

And you can also use Latin characters within your Japanese document.

\vspace{1cm}

\begin{verbatim}
このテキストは、別のフォントを持つことになります

This is a verbatim environment with mono-space font
\end{verbatim}

\end{document}

As you see, to set up a LaTeX document in Japanese is straightforward. Below is a description of each command:

\usepackage{xeCJK}
This includes the package xeCJK which allows to use Chinese, Japanese and Korean fonts in a document to be compiled with XeLaTeX.
\setCJKmainfont{AozoraMinchoRegular.ttf}
The main font of this document. You can either download a font and put it in your current working directory or use one of the fonts already installed in your system.
\setCJKsansfont{KodomoRounded-Light.otf}
Font to be used in elements that require the sans family font.
\setCJKmonofont{KodomoRounded-Light.otf}
Font to be used in elements that require the monospace family font. In the example the text inside the verbatim environment uses this font.

#  CJK with pdfLaTeX

The CJTK package can also be used to generate a document with pdfLaTeX. External fonts can not be used, so compiling with XeLaTeX is recommended.

\documentclass{article}

\usepackage{CJKutf8}

\begin{document}

\begin{CJK}{UTF8}{min}
\section{これは最初のセクションである}

フォントはまた、数学的な形態および他の環境で使用することができる
\end{CJK}

\vspace{1cm}

\noindent
Outside the environment Latin characters may be used.

\end{document}

The line \usepackage{CJKutf8} imports CJKutf8 which enables utf8 encoding for Chinese, Japanese and Korean fonts.

In this case every block of Japanese text must be typed inside a \begin{CJK*}{UTF8}{min} environment. In this environment UTF8 is the encoding and min is the font to be used. You can also use the JIS encoding with the song font.