Below is a list of passwords that can be used in Naruto Clash of Ninja 2 to unlock more playable characters, options, and technqiques. Unfortunately, there's only one actual "cheat" for this game it seems.
Once you have at least 50,000 coins, go to the title screen and press the buttons A(2), B(2), Y, Z, Up, Right, and R. You should then be able to play as Sharingan Sasuke.
Most of the other characters can be unlocked pretty easily, without a code. Either by buying them after reaching a certain stage in the game, or getting them after getting a certain amount of points after unlocking a specific character or completing some part of the game.