To have one of the best offenses which also defends you, keep sliding the all over the enemy sideways, up, down, diagonally, tap them with your stylus to throw knives. Then finish them off by sliding the stylus up, up, then down.
When you have completed the game on the Normal difficulty setting Muramasa's prize shop, Artwork and the Hard difficulty setting will become available options. At Muramasa's prize shop you will be able to view intermission sequences, letters and character files that were found during the game you completed.
Select Normal or Hard difficulty level and survive the fight with Ryu and defeat the dragon boss. When you have done this 'The Way of Kunoichi' mode where you play the entire game as Momiji will become an available option when you begin a new game.