Gaara
Beat Single Player mode with Naruto and Shikimaru
Hinata Hyuuga
Beat Single Player mode with Neji
Ino Yamanaka
Beat Single Player mode with Sakura
Itachi Uchiha
Beat Mission "Rematch Itachi vs. Saskue", after unlocking all other starting characters plus Guy and Kankuro
Kankuro
Clear Mission Mode once
Kisame
Beat Single player with Naruto, Sasuke, Kakashi, Guy and Jiraiya.
Orochimaru
Beat Single Player with Naruto, Sasuke, Kakashi, and Jiraiya.
Shino Aburame
Beat Arcade mode with Kankuro
Temari
Beat Shikamaru's Single Player mode
Tsunade
Beat Single Player mode with Jiraiya