Set the system date to your birthday. When the game is started you will hear a special "Happy Birthday" greeting when you tap the option to start the game.
-Beat the game once to unlock Head Ninja Difficulty
-Beat the game once to unlock Muramasa's prizes to obtain artwork and biographies.
To Unlock Master Kunoichi mode, where you play as the mysterios Kunoichi, Rin:
-Complete the game once
- Start a new game and survive the sparring with Ryu
- Defeat the chapter 1 Dragon boss
Upon completing this and moving to chapter 2, Master Kunoichi becomes selectable.
Beat the game once on Head Ninja Difficulty to unlock Master Ninja Difficulty.
To simply obtain an infinite amount of karma when you are facing the black dragon simply get him down to his last point of health to the point where is one-hit kill attack is used.Instead of using the dragon sword to kill him you can use UT's on him forever and his health will never go down plus he'll never attack you if you're far away from him.
You can get an endless amount of UT's on the red dragon at the beginning of the game with Momiji(assuming you haven't beaten the game at all) since he can't be beaten with Momiji unless you've cleared any difficulty level once.
The only way you can achieve this score is by using UT's on the first phase of Ishtaros(When she's invincible)at the end of Chapter 11.It is best to use a UT on her right at the same time she is about to fire her laser and not a second too late or you may be to close to her to prediict which of the 3 moves she'll use at close range+keep a good distance from her the majority of the time.