Use Kakashi on single player mode or 2 player versus and use sharingan. Note: that you must use Copy Justsu and the opponent from the list must attack you using special technique or special justsu on you still on Copy Justsu. Battle these characters ( Kakashi cant copy all justsu):
1. Naruto (only the Uzumaki Barrage)
2. Sasuke(The fire style:flower justsu is still not tested)
3. Sakura (all of them)
4. Shikamaru (only the Shadow Possesion Justsu)
5. Rock Lee (only the Primary Lotus note if Rock Lee is in the brown skin and use the Hidden Ltus it will still be Primary Lotus) Note: If you battle the ones that are not on the list Kakashi will teleport if the opponents that are not on the list or on the list and not using special technique like punch,kick,etc. and the ones that are not on the list and use special justsu Kakashi will still teleport. I'll get more info. Soon.
Crazy damage
This isn't really a code, more like a better way to play... for the people that may be playing Naruto with a classic or Gcube controller, use the Wii remote and Nunchuck on movement mode. It's sort of hard to transition but you'll get the hang of it in about five minutes. If you follow the directions on the screen when using your special attacks (only works on some) it makes your special attacks much more powerful.
Difficulty 4
Beat Time Attack once, with any character.
Get Voices from Sound Player
Well you have to go Single Player >>> Time Attack. Then choose any character, use it. When you win, there will be an unlock, read the description.
Example: you picked Naruto, and You passed all ten characters from ten battles, you will recieve an unlock from the sound player(after the game show you the time how fast you battle in 10 characters from 10 battles),it says : "You can now listen to Naruto's voice"
(I don't remember where I got the sound player. If you have a sound player, you can hear it)
Mission 20
Beat Single Player with Rock Lee and Neiji Hyuga.
Mission 21
Beat Single Player with Naruto Uzumaki.
Mission 22
Beat Single Player with Sasuke Uchiha.
Mission 23
Beat Single Player with Kakashi.
Mission 23 (another way)
You must unlock all character voices from Time Attack to get mission 23. Do the one cheat title of mine "Unlock voices".
Rasengan
Play "Shadow Clones".
Shadow Clones
Play "Shuriken Training".
Sharingan counter
If you use one of the characters Kakashi can counter using sharingan, it gets sort of frustrating right? when he shouts Sharingan, keep pressing weak attack and you will most likely hit him before he hits you, thus countering his counter.
Survival
Complete "Single Player".
Ultimate deidara
To unlock deidara play gaara in single player mode then play all the missions 1-23 then go into vursus mode and play 2 rounds of 2 player vursus mode then go back in single player mode and you will see deidara in his ultimate form (he will have all 4 mouths showing and 1 arm ripped off and his platnum eye)
Unlock Characters
To unlock Itachi Uchicha, You must beat Mission 23(Rematch-Itachi vs. Sasuke).
To unlock Kisame, Use Might Guy in Single Player Mode,you must get enough high score, you will battle Kisame at Battle 10,Defeat him and you'll get him.
To get Orochimaru and Tsunade, Use Jiriaya at Single Player Mode, you must have enough high score, Then they may appear, defeat them and you'll get them.
To get Hinata Hyuga, Use Neji Hyuga, You must have enough high score she will appear at Battle 10,defeat her and you'll get her.
(I'll get more info. soon)
Unlock characters
To unlock most characters you must select "single player mode" and complete single player (10 battles) with all the starting caracters (Naruto, Sasuke, Sakura, Lee, Jiriah, Kakashi and Neiji). And you must also finish "Mission mode" once in Chunin (you don't have to finish all of the levels of difficulty) Note: there are actualy 23 missions in "mission mode" to unlock them you must fight in single player in "single player mode" with the starting characters. You can also do time attack to unlock the juke box and the voices of the characters.
Unlock timary
You need to beat the game.
Various Characters
Deidara - Beat Story Mode
Itachi - Beat score attack with Kakashi
Kankurou - Finish story mode
Kisame - Beat score attack with Gai
Sasori - Beat score attack with all chracters
Temari - Beat Story Mode
Tenten - Beat score attack with Neji
Note: Story mode must be completed for the first time.