The direct sequel to Makai Senki Disgaea produced in 2013 (10 years after the original), but it is not the fifth game in the series. Rather it functions as a side game taking place a few years after the original game. 'D2' stands for 'Dimension 2'. Laharl, Etna and Flonne reprise their roles as the primary protagonists.
Not to be confused with Makai Senki Disgaea 2, which was the 2006 indirect sequel released after Makai Senki Disgaea.