The following characters become unlocked when you complete the corresponding task.

Unlock Zetsu:
Use Susan-o 5 times with Sasuke in Vs mode.

Unlock Pain:
Beat every mission with each Ataksuki member with a Hokage rank.

This feature becomes available by doing the Ultimate Nine-Tailed Naruto and Second State Sasuke S Rank missions and getting rank Head Ninja or Hokage.

When you have played over 600 battles this feature will become available.

When you reach 30% mission completion for a character their voice will become unlocked.

The following features become available options when you reach the indicated stage of the game in the indicated 2-Player mode.

Unlock 2-Player Time Attack:
Get at least Jonin in 2-Player Score Attack.

Unlock 2-Player Survival:
Get at least Jonin in 2-Player Time Attack.

This feature which is the last bar in 'Extras' lets you view Story mode cutscenes without playing Story mode. It is enabled when you complete Story mode on the Level 4 difficulty.

This feature becomes available when you change the difficulty to level 2 and beat U.N.T Naruto and Sasuke SS Last Missions.

An alternate way to unlock the bonus characters is by fighting in lots of battles. Below is a list of the bonus characters that can be unlocked and the amount of battles you have to have fought before they become unlocked.

Unlock Baki:
Fight in 350 battles

Unlock Anko:
Fight in 350 battles

Unlock Itachi:
Fight in 400 battles

Unlock Kabuto:
Fight in 500 battles

Unlock Kagura:
Fight in 650 battles

Unlock Awakened Hinata:
Fight in 700 battles.

Unlock Kyuubi Naruto:
Fight in 750 battles

Unlock Second State Sasuke:
Fight in 800 battles

The following bonus features become available options when you complete the indicated task.

Unlock Kumite Mode:
Come in 1st place on Score Attack mode.

Unlock Survival Mode:
Come in 1st place on Time Attack mode.

The following bonus characters can only be unlocked when you beat the first 2 missions and the last 3 missions with Jonin Rank or higher for each character.

Unlock Awakened Hinata:
Beat the 1st and 2nd missions then the last three missions with Jonin rank or higher.

Unlock Second State Sasuke:
Beat the 1st and 2nd missions then the last three missions with Jonin rank or higher.

Unlock Ultimate Nine Tailed Naruto:
Beat the 1st and 2nd missions then the last three missions with Jonin rank or higher.

Completing the indicated tasks during the game will unlock the corresponding bonus character.

Unlock Towa:
Complete Story mode.

Unlock Komachi:
Complete Story mode.

Unlock Kabuto:
Complete Baki

Unlock Anko:
Complete Orochimaru's 1st and 2nd missions.

Unlock Bando:
Complete Kabuto's 1st and 2nd missions.

Unlock Itachi:
Complete Sasuke's 1st and 2nd missions.

Unlock Kagura:
Complete Bando's 1st and 2nd missions.

Unlock Kisame:
Complete Itachi, Guy and Asuma's 1st and 2nd missions.

Unlock Kurenai:
Complete Kiba, Hinata and Shino's 1st and 2nd missions.

Unlock Orochimaru:
Complete both Jiraiya and Tsunade's 1st and 2nd missions.

Unlock Baki:
Complete Gaara, Temari and Kankuro's 1st and 2nd missions.

Unlock Asuma:
Complete Ino, Shikamaru, Choji and Kurenai's 1st and 2nd missions.