Play as Kuroko - At the character selection screen in Two Player mode, press Up, Down, Left, Up, Down, Right + X.

Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

1 Round Perfect (5 points): Complete a perfect round in single player arcade mode.
The Samurai (15 points): Complete the single player arcade mode.
The Perfect Samurai (30 points): Complete the single player arcade mode without losing a round.
Man in Black (10 points): Kuroko appeared in game as enemy (CPU).
Point Hunter (10 points): Achieve over 200,000 points in single player arcade mode.
Straight 5 (20 points): Achieve 5 straight victories in online ranked matches.
Straight 10 (35 points): Achieve 10 straight victories in online ranked matches.
Victory 10 (10 points): Achieve 10 victories in online ranked matches.
Victory 50 (20 points): Achieve 50 victories in online ranked matches.
Victory 100 (35 points): Achieve 100 victories in online ranked matches.
Big Apple (5 points): Ukyo Tachibana throws big apple.
Am I Cute (5 points): With any character, enter the "Super Deformation Moves" command to become the doll-like version.