According to Kotaku:
 
The back story for the game, like many Persona titles, involves urban legends and murder. Young men have been found dead in their beds, terrified expressions frozen on their faces. Rumors have begun to surface that if you begin to have a nightmare you must wake up immediately or die. The game starts off with Vincent, our lanky hero, hanging out at a bar with Katherine. Having dated for five years, Katherine suggests the pair gets married. Vincent freezes, as men often do. Then a mysterious girl named Catherine enters the bar and takes a seat next to Vincent. He ends up taking her home and sleeping with her. You can see bits of this in the opening trailer we posted last month. Then the nightmares begin. 
 
Sounds great. It sounds like a true successor to Persona, and I really do want it. Next generation Persona spin off sounds amazing.