Riai is the story behind your kata. It is what gives the movements their meaning and is what the kata should be “saying” to those watching. When the riai changes, the technical aspects of the kata can change quite dramatically. I will illustrate this using the kata Uke Nagashi from the Zen Ken Ren Iaido set.
I first learned this kata with the following story. You are sitting in seiza when an opponent approaches from your left and cuts down on your head. You rise, protecting your head with your own blade and cut him down diagonally.
|Fig 1: Attack happens as you sit in seiza||Fig 2: First move clears your body||Fig 3: Block is "insurance"|
|Fig 4: Strike down||Fig 5: Step back as you cut|
From the first sequence of photos you will see what this looks like. Elizabeth is holding a bokuto where the cut would be made as I sit on the floor (fig 1). Normally she would be attacking from the front but for this illustration she is behind, to mark where the cut happens. As the cut is being made I step forward and draw the blade upward (fig 2) which moves me out of the way of the cut, I continue to raise the blade into a blocking position called uke nagashi as I rise (fig 3). Note that my feet are still in the same place on the floor. Something to consider here is that the blocking movement does not actually need to make contact with the attacking sword, my body is out of danger to the side of the cut. I then bring the right foot up to the left and turn to face the opponent, swinging the sword around and overhead at the same time and gripping the hilt with my left hand (fig 4). From here I cut down diagonally through the opponent as I pull my foot back (fig. 5).
This kata makes perfect sense given the situation where the opponent is cutting down on us as we rise.
|Fig 6: The attack comes later, the swordsman is partially rising||Fig 7: The block must deflect the cut||Fig 8: The blade is turned over|
|Fig 9: The cut begins||Fig 10: The cut finishes with the pull back of the foot|
Recently the instruction in this kata has been slightly different, with the opponent now sitting down some distance away from us, rising to his feet, approaching and cutting down on us. This riai states that we now have more time and more space to react, so we do. Figure 6 shows the me in a half raised position when the attack happens, and Elizabeth has her bokuto marking where that cut would be made. You can see that the cut will not miss my body when I am on one knee as it did before, because the attacking swordsman has adjusted to my movement forward. In this case my defence is to stand and make contact with my blade on the attacking blade to deflect it off line. Figure 7 shows the deflecting position which is achieved at the same time as I bring my right foot up beside my left. You can see that the attacking sword would be cutting into my shoulder if I did not meet it in the deflection. Figures 8, 9 and 10 show the sword swinging around to above my right shoulder, the hit on the shoulder of the opponent and the cut as I pull my right foot back.
So, a small change in the riai (the attacker is sitting down) means a change in the timing and the meaning of the kata, with the raising of the blade into the overhead defensive position happening later, as the swordsman stands up, rather than before the right foot is moved forward. The riai also requires a more definite kime (focus) on the block since the attacking blade is definitely making contact with our blade as we rise.
Overall, the technique remains roughly the same and most people would not pick up the change in timing, but to an experienced iaido student, that timing means something has changed in the riai, the story is different.