[!IMPORTANT] I highly recommend reading the preface for background on the first three kata especially.
Uchidachi and shidachi both start in gedan no kamae and advance starting with the right foot. Upon reaching ma-ai, both raise their kensen under a battle of wills until naturally reaching ai-chūdan. Uchidachi, sensing an opportunity, turns the sword edge slightly to shidachi’s left to make a two-handed thrust to shidachi’s solar plexus by stepping forwards on the right foot and sliding on the shinogi around shidachi’s sword.
Shidachi, taking a big step back leading with the left foot in order to pull the body back and away from the incoming thrust, presses uchidachi’s sword lightly down and to the side with the shinogi of their own sword’s monouchi area in nayashi-ire, and returns the thrust to uchidachi’s chest.
Upon having their attack returned, uchidachi steps back with the right foot and brings their sword below and around shidachi’s sword, and with slightly extended arms brings their kensen in front of shidachi’s throat to press their sword to the right with the monouchi shinogi. The body is facing forwards with the left foot in front.
Shidachi presses on with another step, this time with the left foot, in kuraizume with the feeling of thrusting. Having no choice but to back again, uchidachi steps back with the left foot and brings the sword below and around shidachi’s sword to press it to the left with the monouchi shinogi. However, uchidachi is subdued by shidachi’s kigurai and is forced to lower their kensen while retreating starting with the left foot. Without hesitation, shidachi continues in kuraizume, taking three small steps in quick succession starting with the right foot while raising their kensen to between uchidachi’s eyes.
Uchidachi starting with the right foot and shidachi with the left, both sides return to the centre while assuming ai-chūdan. From there, both sides lower their kensen to release their kamae, and return to their respective starting position.
The third kata teaches the principle of the centre (中心 chūshin) and how to control it. As uchidachi reaches chūdan slightly earlier than shidachi, they find an opening in that shidachi’s centre is unguarded. Exploiting this opening, they thrust while using the curvature of the sword to reach around shidachi’s sword to target the suigetsu1 (solar plexus), keeping the kensen in the centre. The lesson for shidachi lies in steering the tsuki off centre while themselves retaining control of the centre, and then to achieve victory by asserting control of the centre despite uchidachi’s attempts to regain it.
Shidachi’s defence against uchidachi’s tsuki is described as 入れ突きに萎やす (irezuki ni nayasu), and the technique is generally referred to as nayashi-ire (萎やし入れ), meaning to make something wilt by pulling it in. The full description can be translated as “with the monouchi’s shinogi, lightly make uchidachi’s blade wilt in an inwards thrust”2. One sometimes sees this technique performed similarly to the defensive counterthrust in nanahonme, but there is no forwards thrust. Rather, one backs away from the sword, leaving the hands in place until the left foot has completed its step, then pulling the sword in towards oneself as the right foot follows.
Uchidachi’s sword is made to “wilt” (a very fitting description) by turning the edge to the bottom right, thus lightly pressing the blade down and aside with the shinogi of the monouchi, causing uchidachi’s wrists to overextend and lose strength. It is only necessary to push the kensen just outside the line of the body, and it is essential that both hands remain completely centred to keep control of the centre. The execution is very simple - just turn the palm of the right hand to face down as the sword is pulled in. Then, the thrust can be instantly returned by angling the edge back down and applying tenouchi while stepping forwards.
The act of relentlessly advancing and denying uchidachi all their attempts to regain control until they are forced to surrender is termed kuraizume (位詰め). Although uchidachi’s tsuki is returned in a kaeshi-zuki, the purpose of this first thrust is not actually to injure uchidachi. First of all, the thrust is to the centre of uchidachi’s chest; a poor target for a tsuki due to the presence of the sternum. Had uchidachi stayed in place, the blade would have made contact with the body, but what shidachi is really doing is to assume chūdan no kamae and press strongly into uchidachi’s centre. The elbows extend somewhat, but rather than from deliberately pushing the hands forwards, this is due to applying tenouchi to strengthen the grip and assert the kamae.
When uchidachi brings their sword around to press against the ura of shidachi’s sword, this is in an attempt to regain control of the centre. At all times, the body has to be completely facing the opponent. The kensen has to be slightly higher than in chūdan (throat-height rather than chest-height) because shidachi’s sword is too close, and cannot be pressed aside close to the tsuba. It is important here not to turn the sword too far and hit with the back ridge, since the purpose is not to perform a harai-waza, but to reestablish kamae. Regardless, because of shidachi’s assertive forwards action, the attempt fails, and shidachi presses forwards again with overpowering kigurai. The most effective way to gain the centre is to fix the kamae and push forwards like this with the full weight of the body rather than to press down or sideways with the hands, which is difficult and can open one up to counterattacks if the opponent suddenly releases their pressure.
Again having failed to restore control of the centre, uchidachi has no choice but to retreat. Shidachi immediately follows so as not to give uchidachi any chance to break free by increasing the distance. The first step, with the right foot passing the left, is longer than uchidachi’s shorter step with the left, thus further closing the distance between the two sides. After that, the second and third step are shorter than normal to maintain the same very short distance as uchidachi takes shorter steps while backing away. While pursuing uchidachi, shidachi raises their kensen to a threatening position between uchidachi’s eyes, to really hammer in the point, as it were.
The third of the imperial regalia is the sword, Kusanagi no Tsurugi, representing the virtue of valour. In Japanese swordsmanship, the student strives to attain the mental state of mushin (無心) or fudōshin (不動心): the empty and unassailable “no-mind” that naturally adapts to anything the enemy does and cannot be perturbed. By maintaining mushin in the face of danger, shidachi demonstrates unshakable valour, and emerges victorious without bloodshed by breaking uchidachi’s will to fight. This represents the pinnacle of swordsmanship, where the “killing sword” of satsujinken (殺人剣) has been transcended and the student wields the “life-giving sword” of katsujinken (活人剣). It goes without saying that a great deal of skill, courage, and strength of mind is necessary to achieve this ideal of kendō; it is, then, a fitting final step in the student’s development in both proficiency and character.
When uchidachi and shidachi slowly raise their swords from gedan into chūdan after entering into ma-ai, uchidachi is a little ahead of shidachi. One sometimes hears that this is because uchidachi initiates the movement and shidachi simply lags behind, but that makes no sense — after all, nothing stops shidachi from just raising their sword just that much faster. Besides, shidachi never “lags behind” uchidachi; rather, they are like a shadow, moving because the body does and never before it, but also never perceptibly after it. No, shidachi allows uchidachi to reach chūdan first because they do not let themselves get flustered and be goaded into hasty action. By staying calm and not getting provoked by uchidachi raising their kensen a little before their own, shidachi demonstrates mushin. Uchidachi attacks the apparent physical opening in shidachi’s centre, but there is no opening in shidachi’s heart, so the attack can be calmly diverted and returned with a much stronger counterattack to uchidachi’s own centre and spirit.
In this third kata, both sides start from gedan, the kamae of humanity (人 jin), which is the third and final component of ten-chi-jin. Since shidachi has now learnt to break away from the strict structure of basic form and effortlessly adapt to whatever uchidachi throws at them by attaining the state of mushin, their style has progressed to the smoothly flowing sō (草, “grass”) of cursive script in calligraphy. Each stroke flows naturally into the next, and there is no longer any need for rules. The apparent paradox, of course, is that in other to shed the rules, one must practise the basics correctly until one can apply correct technique without any conscious thought; this is true of both calligraphy and swordsmanship.