Play as Yuga (shown above)
From Archon
Go to 1 player mode and put your cursor over Kuroko (i.e. press down once). Press and hold B. You should hear a "bloop" sound, but it will not cancel out to the title screen. Now rotate the controller clockwise at medium speed, making sure to hit all the extremes in direction. You should hear a "bloop" sound each time, if you hear a "clink" then you've gone too fast. The speed is critical and it's pretty slow, maybe a full revolution every second and a half or two seconds. Around the fifth revolution, Yuga will appear where Kuroko's space is. Without letting go of the B button, press A and you can select Shura or Rasetsu.