Byakugan Hinata - Learn new Jutsus until Hinata’s father appears outside Chunin Exam Stadium. Talk to him and go to training field. Talk to Hinata, then return to the stadium. Fight Neji and the character should be unlocked.

Itachi Uchiha - Beat the game to unlock.

Kabuto - Beat up the Might Guy in Kykio Castle during the Gedo Mark Saga to unlock.

Kisame - Beat the game to unlock.

Kakashi Anbu - Beat the game to unlock.

Nine Tailed Naruto - Beat the game to unlock.

Orochimaru - Beat the game to unlock.

Orochimaru Sealed - Defeat Orochimaru with Third Hokage in Konoha Destruction to unlock.

Taijutsu Naruto - Buy a Might Suit for 100,000 Ryo. Then go to Tanzaku Outskirts and talk to the Might Guy. Train there and the character will become unlocked.

Tsunade - Beat up Sealed Orochimaru during the Second Saga to unlock.