You can change the first and last name linked to your Rakuten account by accessing your Account settings.
Accessing your Account
To access your Account, please:
1. Click the "My Account" drop down menu located at the top of any page and sign into your account
2. Once signed in, click on “My Account”
3. Scroll down to the Personal Information section and click "Name"
4. It will then bring you to section where you can edit your name and add a nickname if you would like
5. Enter the first name in the “First Name” field
6. Enter the last name in the “Last Name” field
7. Hit "Save" option