Unlock Very Hard Mode
This difficulty setting becomes available when you beat the game once on the Hard difficulty setting.
Unlock New Game+
This feature will allow you to replay the game with ALL of your upgrades and Skill Points. To unlock New Game+ you must first beat the game. Then save your game and continue from your saved game.
Unlock Insane Mode
This tough difficulty setting becomes available when you complete the game in any difficulty.
Unlock Extra Costume
When you beat the game once the Costume option on the 'Main' menu will become available and you will be able to select the Miko costume for Misa.