P4U
Welcome to the Persona 4: Arena Wiki
Publisher: Atlus
Developer: Arc System Works
Genre: 2D Fighting game
Release: "March 1, 2012" (Arcade, Japan), "Summer 2012" (PS3/360, Japan, North America)
Forums @ Mayonaka Midnight
What is P4A?
Persona 4: Arena (or P4A for short) is a special collaborative effort between Atlus (known for their fine works including the numerous Shin Megami Tensei games, of which the Persona series is apart of) and Arc System Works (best known for their beautiful 2D sprite fighting games including Guilty Gear and BlazBlue).
P4A is a fighting game but isn't a mere "spin-off," it is a full fledged entry into the Persona canon and Atlus is working very closely with Arc System Works to make sure everything goes well. The home version will even feature a fleshed out story mode which ties directly into the original game. So in many ways this is a sequel, just in a different form.
Also even though "4" is in the title, several characters from Persona 3 make an appearance as well.
Story
Two months after the events of Persona 4, Teddie suddenly disappears. The Investigation Team members then start watching the Midnight Channel once more in hopes of learning about Teddie's whereabouts, which leads them to find the bear promoting a fighting tournament by the name of "P-1 Grand Prix" in order to discover the Ultimate Persona user. The characters are surprised by this, so they decide to get together once more and enter the TV World to find out what happened to Teddie and to also participate in the tournament.