Unlock Extra Characters
Rock Lee - Beat Zaibuzan in story mode without using continues, and then beat Rock Lee when he appears.

Kyuubi Naruto - Unlock Rock Lee, and then beat the game with all characters. Now highlight Nartuto on the character select screen and press X or Z.

Sharingen Kakashi - Beat the game with Kyuubi Naruto, and then beat the game with Kakashi. Now highlight Kakashi on the character select screen and press X or Z.

Alternate Costumes
On the character select screen, highlight a character and press Y.

Unlock Sound Test
Beat the game with every default character.

Unlock Hinata
Clear story mode using Sakura. Find this fighter by highlighting Rock Lee and pressing X.

Hint - Survival Mode Hokage Ranking
Survival Mode is pretty hard in Naruto Clash of Ninja in my opinion. So, I am going to give you some tips, hints, and strategies to help you get a Hokage Ranking in Survival Mode.

If you have unlocked Demon Fox Naruto, I recommend using him. I recommend Demon Fox Naruto because:

1. He does a bit more damage than average with every hit to your enemy. Therefore, you do not have to land as many of your attacks.
2. He has a long Special Jutsu that does more damage than average.
3. He gives you the upper hand when it comes to Chakra.

You will start to notice the difficulty is going up as you fight enemy twelve or so. I recommend using as many Special Jutsues as possible after you defeat enemy eleven.