Kirikaeshi, whilst not universally loved, is one of the most beneficial kendo training exercises. As an experienced kendo practitioner, I still find it painful and exhausting, that is, when done correctly; which of course, is the only way to do it.
It helps improve, cutting, footwork, breathing and kiai and most importantly the union of all of these in ki-ken-tai-ichi. It can be practised as a kihon drill or at the beginning or end, (sometimes both), of keiko with your instructor.
Most people are used to the sequence of shomen and four yoko-men cuts going forward, followed by five yoko men attacks going back; with the pattern repeated before moving through with a final shomen attack. This is usual but, by no means the only method; with various permutations of cuts backwards and forwards being equally acceptable. In fact, kirikaeshi can be moulded to match the space available and is sometimes conducted up and down the length of the dojo. Kirikaeshi can also be adapted to practice dou uchi or a mixture of dou and men strikes.
Whatever the format, the elements of kirikaeshi should remain the same. You should start from issoku- itto-ma. Some teachers suggest stepping back to adjust distance. Personally I am not a fan of this idea, as stepping back weakens your approach and intention. From Issoku-itto-ma, you should step into your own cutting distance, lifting your left hand up above your mengane to strike a correct, kihon shomen; paying attention to ki-ken-tai-ichi.
There ar two schools of thought on the next step. One suggests that you should make firm tai-attari before mottodachi receives the sequence of yoko men attacks. The other requires you to just gently touch mototodachi as the signal for him to move back. I would suggest this latter approach for less experienced players, as you do not need to worry about applying power to make body contact, but can instead concentrate on striking yoko men correctly.
Always start by striking to the right and also ensure that you lift your left hand above the mengane as for shomen. There is a tendency amongst beginners to try to hit quickly by not lifting the shinai sufficiently. This must be resisted, as must the desire to hit quickly with the hands if your foot and body movement is not equally fast. It is also tempting to bounce or jump with both feet in a fixed position. This is also a no-no, with the imperative being on correct footwork, with the back foot coming into position at the same moment as you make the strike.
The cut itself should be at 45 degrees, so that you hit between the 3rd and 5th mengane. The shinai should be raised straight through your centre, using relaxed hands to guide the hassuji to the target.
Kiai and breathing are important. You should fill up with air, letting some out in your kakigoe whist in issoku-itto-ma and then aim to breathe out continuously through the first shomen and the next 9 yokomen. So the sequence should be ya—men—men,men,men,men,men,men,men,men,men—men: in one breath. This is followed by a quick intake of air and then repeat.
When you return from the final yoko-men to starting distance you should take pains to do so in suriashi,(backwards of course), whatever you do, do not walk backwards’ crossing your feet. On the final shomen, motodachi should step to the side and you should go through to safe distance with good zanshin.
For motodachi it is important that you receive the cut as close as possible to your own men allowing kakarite to aim correctly rather than stopping the cut to hit your shinai. You should also try to receive with the shinai to the opposite side to your leading foot, otherwise you risk looking like Robocop.
For a demonstration of correct kirikeishi have a look at this YouTube clip of Yanai Norimitsu sensei at a seminar in Ireland. http://www.facebook.com/l.php?u=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D65kqpj281nI&h=47185