New Disgaea Infinite details from Siliconera - "Disgaea Infinite borrows the gameplay system from Infinite Loop, a Japan-only text adventure game Nippon Ichi developed for the PSP, and stars characters from the Disgaea universe. Laharl, Etna, Flonne, Mao, and Raspberyl are in the game.
But, none of them are the lead character. The story is about one Prinny's long day trying to solve an attempted murder mystery. This particular Prinny gains the ability to possess other characters and hear their thoughts, abilities the Prinny will need to use to find the truth."
Also see four videos of the game at the link.