$ sudo apt-get update
$ sudo apt-get install mrxvt-cjk 

mrxvt-cjk is installed in your system.

Make ensure the mrxvt-cjk package were installed using the commands given below,

$ sudo dpkg-query -l | grep mrxvt-cjk *

You will get with mrxvt-cjk package name, version, architecture and description in a table

mrxvt-cjk package basic information: