Press Up(20) when "Press Start" flashes at the title screen. Start the game and complete it in circuit mode to get ???'s Z Medicine as a prize.
Enter QSF??[circle]B[spade]C~GJHCGL?[heart]?BKBV as a password. Suzaku will have more items, ten medals and Bokuchin and Ryumuao will be unlocked.
Successfully complete the Ryumaou Tournament as Yuka at Rank S with 60 second, two round and normal difficulty settings. Note: You must already have nine medals.
Highlight the "Easy" difficulty option, then repeatedly tap Left until "Very Easy" is displayed
Defeat Bokuchin during the game.
Defeat Ryumaou in the Ryumaou tournament
Successfully complete SD Hiryu mode as Ryumaou. Repeat this until receiving the random Skull of the Devil King prize. This will unlock Ryumaou at the Virtual Hiryu screen.
Highlight the "Hard" difficulty option, then repeatedly tap Right until "Very Hard" is displayed
Select Wiler and do his Wiler Bomb any other bomb with a character on Bokuchin. He will wear a new black suit briefly.
Select Ryuhi and do his Super Kinryuha do Robo No Hana. His belt will turn red briefly.
Select "SD Hiryu" mode and fight in the circuit. Defeat a platinum character to earn a medal. The platinum characters will be playable after all ten medals have been collected.
Press Down(20) when "Press Start" flashes at the title screen. Start the game in SD Hiryu mode and win a tournament to get a rare item.
Earn nine medals to play in the Ryumaou tournament.
Enter RVC?[Diamond]VB[Square]C[Circle][Circle]JBWFL[Club][Heart]RBM[Circle]F as a password. Suzaku will have more money and stronger items, and you should be able to use Ryumaou and Virt. Ryumaou.