Hold L1 at the character selection screen and choose a character. The hidden characters may be combined to form new teams.

Classic Art of Fighting Team
Robert Garcia (King of Fighters '94)
Ryo Sakazaki (King of Fighters '94)
Yuri Sakazaki (King of Fighters '94)

Real Bout Fatal Fury Team
Andy Bogard (Real Bout 2)
Joe Higashi (Real Bout 2)
Terry Bogard (Real Bout 2)

Orochi New Faces Team
Orochi Yashiro Nanakase
Orochi Shermie
Orochi Chris

Single Entrants
Kyo Kusanagi (King of Fighters '94)
Mai Shiranui (Real Bout)
Billy Kane (Real Bout)
Omega Rugal