Press Down, Up, Down, Up, Left(2) to display the password menu. Then, enter one of the following passwords to unlock the corresponding character.

Character	How to unlock
Play as Gaara	Enter "Sand Box" as a password to unlock Gaara.
Play as Itachi	Enter "Sharingan Demon" as a password to unlock Itachi.
Play as Might Guy	Enter "Youth" as a password to unlock Might Guy.
Play as Temari	Enter "Strong Wind" as a password to unlock Temari.
Play as TenTen	Enter "Ninja Tools" as a password to unlock TenTen.