I'm not sure if this is a parody, so I'll leave it up to you guys to decide.

I also believe this is the first picture for Vietnamese tag...

I can't speak Vietnamese, but now that you mention P4, it sure looks similar huh.

I'm having flashbacks to that Chinese "Olympics Haruhi."

Oh dear god. I took me awhile to realize the person in the back left was not, in fact, a man, but Chie.

I get the feeling this is just a coincidence. :/

No, it's a parody.

Anyway, I provided a rough translation. Just a note, đảng means "party", "group" or "gang" but I think "friends" is a better translation in the context of Persona.
I don't know what the bottom sign says because half of it is cut off but I think it says something like "...pray for a 1000 years...

I thought the bottom line was something to do with Hanoi's 1000th year anniversary of founding...? I was there at the start of this year... Hanoi, BTW, was founded in 1010.

mừng đất nước = happy country , mừng đảng = happy band , mừng xuân = greeting spring ( or mean happy new year for what is coming soon ) and the bottom " kỷ niệm 1000 năm thăng long hà nội " is 1000th anniversary of Thang Long , Hanoi ( thang long is the name of viet nam in the past )

This is just a coincidence, Persona 4 was released in 2008 but this poster was there in 2006 or earlier. (I'm a Vietnamese)
@kazumagvn: Thăng Long was the name of Hà Nội, the capital, Việt Nam name at that time was Đại La.

OH. MY. GOD.