Oh. I just catch what mistake I had made.
I thought MTeX2 English version is all I need to run MTex2.
When I installed both the Japanses MTex2 and the English version, the tool showed up in Plug-In of EmEditor. Thanks for your help.

How about clarifying this point in the website of MTex2 for beginners, like me, of this wonderful tool?

Daehyok Shin