The Netherworld - a place darker than a pitch-black cave, located deeper than the depths of the seas. It is a cursed land where evil reigns and foul beings dwell. Nobody knows its whereabouts, but everybody fears its existence... The story takes place two years after the death of King Krichevskoy, the ruler of the Netherworld. His son Laharl slept for two full years, unaware of his father's death, while demons fought for supremacy over the Netherworld. With the help of his vassal Etna and her underlings, the egocentric, megalomaniac Prince Laharl fights his way to become the next king.

• With Disgaea PSP you can customize the multi player mode. Changes can be made to the game rules, field conditions, win/loss conditions, and many more.
• The word strategy takes on a new meaning with geo cubes. By enabling this feature you select 10 geo cubes that have special effects like level up, stop enemy movement, gain the ultimate weapon, and etc. Then from the 10 you chose, 5 are randomly dealt to you and the same for your opponent. You can see the 10 cubes your oppoent selected, but you do not know which 5 they gained.
• By connecting to your friend’s PSP you can buy or sell your items. However, unlike an ordinary transaction the seller will not gain money or lose their item. You can think of it more as a way to share your item data with your buddies.
• Exclusively for the Disgaea PSP, a whole new story mode dedicated to Etna has been added. In this mode you will play as Etna and try to become Beauty Queen Ultimate Overlord Etna. If you are able to defeat the game in this mode, an exclusive ending awaits the player.
• Part of the fun of is unlocking hidden characters. In Disgaea PSP, you will see familiar faces from a number of previous titles.
• At Laharl’s castle there is a hidden music shop where you can purchase soundtracks and play them in the item world as background music.
• The basic flow of the game is kept simple. You open the game with the story that sets the setting. Once you learn your objective you will prepare for battle and fight the enemy.
• Battles will take place on a grid based field map. Your units will be dispatched and controlled on your battle phase. Once you finish all of your actions, you will end your turn and it becomes the enemy’s turn.