When selecting your character for a two-player game, with the cursor on Haohmaru, hold Start and move the cursor to each character in the following order: Genjuro, Basara, Kyoshiro, Ukyo, Rimururu, Haohmaru, Shizumaru, Nakoruru, Hanzo, Amakusa, Gaira, Galford, Shizumaru. With the cursor on Shizumaru, press A and B.