Enter this code while playing to drop your weapon. The primary uses of this is that sometimes the CPU enemy will do the same.
Also, winning a match without a weapon equipped (it can also be knocked from a character's hands by powerful moves) will result in a different victory animation.
At the main screen, hold down Start, highlight Options, and press A to enter the Options menu. Highlight Exit and press A + B + C + D simultaneously, and release Start.
In 2 player, player 1 should highlight Haomaru and hold D, and press A. For player 2 to get this to work, instead highlight Genjuro and hold D and press A.
Press Left, Right, Down + Start while you're in a match.
Zankuro is available only in 2-player mode. Hold D and press A at the character select screen and Zankuro will be your current fighter.