Instructions
On the PlayStation 3's main menu, choose to create a new user account. The option for creating new user profiles is located on the leftmost section of the main menu.
Enter a new username for your Japanese profile and log in as the new user.
Choose to sign up for a PSN account. The option for creating a new PSN account is located toward the right of the menu, above the icons for the Internet browser and Internet search.
Choose to create a new user and select Japan as your country of residence.
Enter a new PSN account name and email address. Since emails must be unique for all accounts, your email address must not be the same address you used for your original account.