When I start to use new PC that I cleanly installed Windows 10 Fall Creators Update, I found that there was no Japanese locale.
$ locale -a
C
C.UTF-8
en_US.utf8
POSIX
$
I tryed to install Japenase locale using apt command, but I did not know the pakacke name of Japanese locale. Then I use a search engine, I found following blog page.
ubuntuで（できるだけ）全部のlocaleを追加する
https://qiita.com/inayuta/items/a057020f5d836329b804
language-pack-jaをインストールしてもいいです。
root@localhost # apt-get install language-pack-ja
The answer is simple...
