I need to play this mooooore today.
You can play it on your US account, but I don't believe there is any way to bring your save over to your JP account. You'll probably have to play through it again... I'd love to be wrong.
Yes! I don't think you'll be disappointed. If you buy that, you will get an email with the code, yes. It could be a little cheaper here, though. And keep in mind that if you buy it on PSN, you can only use it on that account!
Senran Kagura is, I believe, 5980 yen on PSN.
Odd.
I bought a used vita game in japan and it told me that this deactivated the trophies, but I could simply use the save files.
One more question:
Will I be able to get the patch on a non JP account?