For G Suite.
For Office 365.
How can I change the language for HDE Secure Transfer?
Beside Japanese, this Service supports English.
If [Languages other than Japanese] is more often chosen than [Japanese] for the browser settings, it automatically will be displayed in English.
The language settings part for each browser is as follows;
[Settings] menu -> [Display the advanced settings…] -> [Language settings and input setting] under [Language]
[Tool] menu -> [Option] -> [Contents] tab -> [Language settings] under [Language]
[Tool] menu -> [Internet Option] -> [General] tab -> [Language] under [Design]
The setting procedure may be different depending on your using browser version.