Originally posted by mcgo
I heard you can do this if you make a Japanese account.
You used to be able to, but not any more. You can change your PSN for offline games and on your XMB, but your original PSN will show up in online games and on your friends' list
If you have an original Japanese account, then you can still change your online PSN, but if you made your Japanese account after they changed it, the above applies