Blood and Mai
At the High Scores screen press A+D on controller 1 at the
same time as you press B+C on controller 2. Now go into the
game and will notice blood and Mai!

Burnt Clothing
Choose anybody that has a projectile attack for example
Ryo or Kyo. Then select king or Yuri Sakazaki as your
opponent. Keep on using your projectiles until they have
no more health. When the last projectile hits the opponent,
some of their clothing will break.

REMEMBER: It will only work on King or Yuri Sakazaki.