Unlocking Characters in Naruto USA
All in Heroes mode:

Gaara: Leaf Destruction!! (Normal)
Itachi & Kisame: Atatsuki Returns (Insane)
Kakashi & Guy: Survival Exercise (Easy)
Tsunade, Orichmaru & Jiraiya: The Legendary Sannin (Hard)

Hidden Team Skills
Use the following custom made team characters in Heroes Mode to unlock a new skill. The characters can be selected in any order.

Akatsuki: Itachi and Kisame
Association of Ninja Thugs: Itachi, Kisame, Orochimaru
Aurora of Legends: Orochimaru, Tsunade, Jiraiya
Author & Fan: Jiraya and Kakashi
Eternal Rivals: Kakashi and Guy
Hard Work United: Lee, Naruto, Hinata
Hidden Spikes: Any Team combo
Hot Blood Master & Student: Guy and Lee
Indonmitable Guts Points x 2: Naruto and Jiraiya
Maidens In love: Ino, Sakura, Hinata
Proof of The Existence: Sasuke, Naruto, Gaara
Sharingan to the Max: Sasuke, Itachi, Kakashi
Team Byakugan: Neji and Hinata
Team Genius: Neji, Sasuke, Shikamaru
The Cursed: Orochimaru and Sasuke
Triple Trouble: Naruto, Kiba, Chouji
Uchiha Clan: Sasuke and Itachi