Not against the ToS at all. Create a new account, go to the PSN store, select the top option (forget what it's called), and change region to Japan,etc.
Japanese/EU games will still be available on your PS3 to other accounts. Actually, the PS3 is totally region free - you can import a game and it'll run great. Some games are separated by region in different ways, but typically it's US/Europe/Japan. Be aware that if you buy the EU version of a game, for example, you won't be able to play that same game with people who have US-based disks. Zavvi.com has a lot of deals on games, especially on their "monday madness" sales...and even with shipping it often works out to be cheaper to order the EU version of a game. I wouldn't do this with online games, but I was very tempted Star Ocean.
Trophies by region are also seperate. If you love a game like Demon's Souls (or trophies?)...you can snag the EU version (such as that VERY sweet-looking black phantom edition they have) and snag the trophies all again.