Disgaea 4: A Promise Unforgotten is a tactical role-playing game and the fourth in the Disgaea series by Nippon Ichi Software. The game tells the story of Valvatorez, a former tyrant leading a party to rebel against the president of the Netherworld. The game was ported to the Playstation Vita and released under the name Disgaea 4: A Promise Revisited in the west.