The way I have done is via CPanel. I log into my CPanel account 

> (www.yourwebsitename.com/cpanel) >> public folder >> app >> locale >>
> translations.

 Then, you shall create a folder for the desired translation; something like **jp_JP**. **Create/upload** a .**csv** file with the original languade between " " followed by a ; symbol and the word in Japanese, between " ".

From this way, the translations will run accordingly if you change the languages.

Best regards.