Currently, the PlayStation Store is region free in the sense that users can register for an account in another region such as Japan or Europe, even if the region code of their console does not match the region they are signing up for.
Will this change once the new PlayStation Store rolls out on April 17? The answer is a reassuring no. According to a SCEA representative, if you have multiple accounts in different regions, you will still be able to log-in and download content from those regions without any hassle.
New PlayStation Store not region locked [Gaming-Age]