If you want to use Unicode support included in Mule-UCS package,
please put one line as below:

(require 'un-define)

in your .emacs, site-start.el, or any other start up configuration file.
If you want to use auto detection feature on UTF-8/16, add one more:

(require 'un-tools)

See ${PREFIX}/share/doc/mule-ucs/README.Unicode for details.

If you want to use BIG5 conversion support, add the below line either:

(require 'big5c-ucs)

or

(require 'big5c-cns)

to your .emacs depends on which conversion methods you would like to use.
See ${PREFIX}/share/doc/mule-ucs/README.big5conv for details.

If you want to use JIS X 0213 support, add the following line:

(require 'jisx0213)

to your .emacs. See ${PREFIX}/share/doc/mule-ucs/README.jisx0213
(written in Japanese) for details.

Mule-UCS is installed under the following directory:
	${PREFIX}/share/emacs/20.x/site-lisp/mule-ucs/	--- Mule-UCS