This article explains the behavior where the Salesforce Backup user interface appears in English and cannot be changed to Japanese.
Salesforce Backup currently supports only English. Therefore, even if the language setting of the Salesforce organization is set to Japanese, the text within the Salesforce Backup application will appear in English.
There is currently no feature or setting to change the display language to Japanese. This is expected behavior based on current product specifications.
005263961

We use three kinds of cookies on our websites: required, functional, and advertising. You can choose whether functional and advertising cookies apply. Click on the different cookie categories to find out more about each category and to change the default settings.
Privacy Statement
Required cookies are necessary for basic website functionality. Some examples include: session cookies needed to transmit the website, authentication cookies, and security cookies.
Functional cookies enhance functions, performance, and services on the website. Some examples include: cookies used to analyze site traffic, cookies used for market research, and cookies used to display advertising that is not directed to a particular individual.
Advertising cookies track activity across websites in order to understand a viewer’s interests, and direct them specific marketing. Some examples include: cookies used for remarketing, or interest-based advertising.