Configuration changes made in localectl are not reflected

I'm the first person to work with virtual OS and Linux.I have a question about CentOS 7.

From here, I got CentOS 7.0 x64 (third from the top as of April 14, 2016) as a box and started and up with Vagrant.

vagrant box add centos7 https://github.com/tommy-muehle/puppet-vagrant-boxes/releases/download/1.1.0/centos-7.0-x86_64.box
vagrant init centos7
vagrant up

TeraTerm now connects to this virtual OS and allows input from the shell.

At that time, the contents displayed on the shell were in German, so we configured the locale according to the contents of the link below.

[CentOS] Checking and Changing Locale in CentOS 7
http://zero-config.com/centos/changelocale-002.html

When I checked the configuration, I saw the following:

[vagrant@localhostopt]$ localectl status
System Locale:LANG=ja.JP.eucjp
VC Keymap:de
X11 Layout:de
X11Model:pc105
X11 Options:terminate:ctrl_alt_bksp

However, for example, if you typed the wrong command, the warning text remained in German as follows:

[vagrant@localhostopt]$ la
-bash:la:Kommandoniccht gefunden.

The same was true when I changed the keymap to us.
Is this a specification?Or is it possible to change it?

As it may be related to how the OS and shell work, I would appreciate it if you could provide me with additional documentation that shows the contents.

For your information...
locale results

[vagrant@localhost~]$ locale locale —Cannot set LC_CTYPE to default
locale:No such file or directory locale:Cannot set LC_MESSAGES to
default locale:No such file or directory locale:Cannot set LC_ALL to
default locale —No such file or directory LANG=ja.JP.eucjp
LC_CTYPE="ja.JP.eucjp"LC_NUMERIC="ja.JP.eucjp"LC_TIME="ja.JP.eucjp"
LC_COLATE="ja.JP.eucjp"LC_MONETARY="ja.JP.eucjp"
LC_MESSAGES="ja.JP.eucjp"LC_PAPER="ja.JP.eucjp"LC_NAME="ja.JP.eucjp"
LC_ADDRESS="ja.JP.eucjp"LC_TELEPHONE="ja.JP.eucjp"
LC_MEASUREMENT="ja.JP.eucjp"LC_IDENTIFICATION="ja.JP.eucjp"LC_ALL=

locale-a results (partial as it is too long)

[vagrant@localhost~]$ locale-a locale —Cannot set LC_CTYPE to
default locale:No such file or directory locale:Cannot set
LC_MESSAGES to default locale: No such file or directory locale:
Cannot set LC_COLLATE to default locale: No such file or directory C
POSIX aa_DJ aa_DJ.iso88591