How do you unlock all of the locked characters?
Games Guru: As far as I can tell, this game has three unlockable characters: Rock Lee, Kyuubi Naruto and Sharingan Kakashi.
To get Rock Lee, you have to make it all the way through Zabuza in the story mode with no continues. After you beat Zabuza, you get a shot at Rock Lee. Beat him, and he’s yours.
To unlock Kyuubi, you need to beat the entire game twice with each character in single-player mode.
After you unlock Kyuubi, play the single-player mode one more time as Kakashi. Once you win, Kakashi will be unlocked.