- Bonus classes
Successfully complete the indicated task to unlock the corresponding class:

EDF Soilder	Get level 30 or higher in Gun Weapon Mastery.
Star Skull	Get a Fire, Ice, and Be victorious ind Skull all to level 5.
Star Mage	Get a Fire, Ice, and Be victorious ind Mage all to level 5.
Angel	Get a Female Cleric, Knight, and Archer all to level 100 or higher.
Strider	Get two Warriors or Fighters to level 5.
Archer	Get level 3 or higher in Bow Weapon Mastery.
Scout	Get two Fighters or Warriors (male or female) both to level 5 or higher.
Ronin	Get a Female Warrior and Female Fighter both to level 20 or higher.
Rune Knight	Get a Female Warrior and Female Magician both to level 10.
Galaxy Mage	Get a Prism Mage to level 50.
Samurai	Get a Female Warrior and Female Fighter both to level 20.
Prism Mage	Get a Star Mage to level 35.
Knight	Get a Female Warrior and Female Mage both to level 10 or higher.
Prism Skull	Get a Skull Mage to level 35.
Galaxy Skull	Get a Prism Skull to level 50.
Ninja	Get a Male Fighter and Male Warrior both to level 10 or higher.
Majin	Get a Male Warrior, Brawler, Ninja, Rogue, and Scout all to level 200 or higher.
Thief	Get a Fighter and Warrior both to level 5.

- Etna mode
At the title screen, highlight the 'New Game' option, then push X, Y, B, X, Y, B, A. If you entered the code correctly, you will hear Etna's voice. Alternately, successfully complete the game after reading Etna's entries in her secret chamber. To enter Etna's secret chamber, press the two secret buttons in Laharl's Castle. The first button is behind the throne. The second button is inside the skull on the counter in RosenQueen's store. After both buttons are pressed, go to the room where Longinus, Ghoss, Stigma, and Gargo are usually found. Push A in the corner behind Stigma to reveal the door.

- Bonus characters
Successfully complete the indicated task to unlock the corresponding character:

Priere	Reach Rank 8 in the Dark Assembly, pass the 'Alternate Netherworld' bill, and complete all the stages.
Rozalin	Successfully complete the 'Demon Hall Mirror' stage in the Cave Of Ordeals seven times.
Plenair	Successfully complete the game, talk to Plenair, then choose the blank option
Marjoly	Reach Rank 9 in the Dark Assembly, pass the 'Mysterious Seal' bill, and complete all the stages.
Adell	Successfully complete the 'Demon Hall Mirror' stage in the Cave Of Ordeals six times.
Zetta	Pass all the enemy bills, get Gordon into your party, then complete the first stage in 'Stellar Graveyard' again.

- Adell and Rozalin
Use the following steps to get Adell and Rozalin from the second Disgaea on your team. First, successfully complete the Cave Of Ordeals. Once this is done, the Demon Hall Mirror will be available. Do this level four or five times, and you will have to fight Adell at level 2,000; then Adell at level 2,000 and Rozalin at level 2,500 at the same time. When they are defeated, they will join your party. Demon Hall Mirror will also become a good leveling up location.

- Alternate endings
Successfully complete the indicated task to unlock the corresponding ending:

Midboss	Lose to the mid-Boss of Chapter 1, 4, 6, or 10.
Item God	Kill an Item God or Item God 2.
Normal	Have at least one ally kill and do not fulfill the requirements for any other ending.
Good/Best	Successfully complete the game without any ally kills.
Etna Heroine	Get at least 100 ally kills before Chapter 5, Stage 4, then kill Maderas when prompted.
Flonne Tragedy	Get at least 50 ally kills before Chapter 3, Stage 4, then kill Hoggmeiser when prompted.
Dark Assembly	Force proposals in the Dark Assembly fifty times.
Overthrowing Earth	Pass the 'Human World' proposal at the Dark Assembly, then complete the Human World stages.

Successfully complete the indicated task to unlock the corresponding ending in Etna mode:

Beauty Tyrant Overlord Etna	Pass the proposal for Alternate Netherworld and The Mysterious Seal in the Dark Assembly, then defeat Priere, Marjoly, and Baal.
Normal	Successfully complete the last chapter in Etna mode.

- Plenair
After losing to the mid-Boss and begining a new game, speak to Plenair, and go through the Dark Assembly Tutorial. Speak to her again. When your options appear, there will be a blank space above the 'Exit' option. Push A on it, and Plenair will say something similar to 'They've found me...' and automatically join your party at level 1. She has incredible speed, uses guns as her main weapon, and already has the Nether 35 and an Imperial Seal equipped. Her first special attack is Usagi Drop, which is just about the same as Prinny Barrage but with bunnies.

- Overcomeing Item Gods
Once you go into the stage, look at the bonuses for invincibility geo spots. Use your characters to steal all those spots. Then, try to find an area to pin the Item God in, and just whittle his health down. You can use this method to kill Item God 2 in the Aracadia. Depending on your team's level, you could be a long fight, but you cannot lose.

- Prinny commentary
Successfully complete the game, then begin a new session using your cleared saved game file.