Sega Saturn Cheats - Sokko Seitokai: Sonic Council

Fight as Shibata:

Successfully complete story mode five times using any five characters to unlock the Boss, Shibata, as a playable character.

Fight as alternate Ai:

Successfully complete the story mode as Shibata to unlock an alternate version of Ai. Highlight Ai then hold Start and press A at the character selection screen.

Alternate voices:

Successfully complete the story mode as Shibata. Enter the options menu to switch between type A or B voices.