Atlus has revealed that Persona 4 Arena will be region-locked for the PlayStation 3. This will be one of the very few instances that gamers in the Western hemisphere won't be able to play the Asian PAL version, and vice versa with NTSC.
The publisher would not reveal why this is being done in a statement in the official forums, stating, "Yes, the PS3 version game will be region-locked. I certainly can't offer details as to why, but there might be an official response at some point...
"...To reiterate, our version of the game works for the North and South America regions. Also keep in mind that both the NA and JP versions have both English and Japanese text/voice options, making them nearly identical. I'm unsure of what the case will be for the EU version."
Personal 4 Arena is due to be released on PlayStation 3 and Xbox 360 on the 7th August, 2012 in North America, and the 31st August in Europe.