There's Some Disgaea 4 in My Disgaea 3: Absence of Detention
Disgaea 3: Absence of Detention is the upcoming PlayStation Vita remake of the original title, which released on the PlayStation 3 back in 2008. In true Nippon Ichi style, there are tons of cross-over characters, and both Fuka and Desco from Disgaea 4 are making an appearance in the PS Vita incarnation of Disgaea 3.
Both characters will be in the game as bosses. After you beat them into submission, they’ll be able to join your party. Who wouldn’t want to join you, I mean, c’mon. Disgaea 3: Absence of Detention will be out in Japan almost right in line with the PS Vita release there in December, and it’s already been announced for a Western release by NIS America because they know we can’t have a Sony system without Disgaea.