Unlock Minazuki Zankuro as a Playable character in 2-Player Mode:
Choose Versus mode and enter the 'Character Selection' screen. Then hold 'Start' and highlight the following characters in order. Haohmaru, Genjuro, Basara, Kyoshiro, Ukyom Rimruru, Haohmaru, Shizmarum Nakorurum Hanzo, Amakusa, Gaira, Galford, Shizmaru.

Let the timer to reach '03' when Shizmaru is highlighted and press A + B. Minazuki Zankuro will then appear and be available for selection in the center of the bottom row of fighters.