Disgaea D2 - 2 New Disgaea: Hour of Darkness Story Videos
Since Disgaea D2 takes place directly after the events of Disgaea: Hour of Darkness. Nippon Ichi made two new digest videos that summarize the events from Hour of Darkness. The videos are in Japanese but you can more or less follow the plot.
Disgaea D2 is set to release on March 30th in Japan.