Also, "Shomen Uchi Ikkajo," Sam Combes, Aiki-do, Volume 2, Black Belt Video, 1999.
Also see Gary Simpson, "Karate by the Book," BLITZ Magazine Vol. 22 No. 1, January 2008, p. 74-78 for Clayton interview on H. Yondan.
Step 1-4 of H. Yondan is the two open-hand double blocks plus the following juji-uke (X-block) and morote-uke (reinforced block).
Uchi Komi Dori, Shomen Uchi Ikkajo
As you might expect, the applications for the opening of H. Yondan augment those presented for step 1-3 of H. Nidan. It is a continuation of the same lesson in tachi dori, sword stealing.
Non-Shotokan styles take the hands up on the left to the double-shuto block position (step 1), and then transition across the top to the right side (step 2) without bringing the hands down to the left hip in between. (See the "perspective" article, step 1-4.) This suggests that the Shotokan kata has been modified for unknown reasons. The historical application probably swept the hands up, across, and down.
This is the signature of a Hakkoryu jujutsu technique called uchi komi dori. Aikido students will recognize it as shomen uchi ikkajo. This technique lets you step to the outside of a descending blow, deflect it away from your head, and capture the attacker's arm, usually in a ikkajo arm bar and wristlock.
The explanation I favor for step 1-4 of H. Yondan comes from Steve Chriscole over in England. Steve's expertise combines karate and kendo.
The opponent attacks from your left in step 1. He attempts a shomen uchi, a vertical cut at your head with this sword. Shift toward him (tai sabaki), because you need to get out from under the blade and engage his arms. Your right hand closes over his right hand where it grips the handle of the sword, up against the guard (tsuba). Your left hand engages his right arm just above the elbow. Don't try to stop his swing. Just guide it across and down, locking his arm in an ikkajo arm bar.
- This is your opportunity to branch to the many self-defense techniques that arise from the arm bar, even though they are not illustrated in the kata. You can disarm, capture or maim him as the arm bar allows.
Step 2 of the kata is similar but offers a slightly different lesson. (See the photos on the third page of the BLITZ article.) Your left hand grips his right hand, up against the tsuba. Your right hand grabs his left hand, which gives you control over the pommel of the sword. Using an "X" block motion, take the sword down to waist level and push the pommel away and down. This rolls the sword into a point-down position, pommel up, and then flips the blade up between the swordsman's legs, which will worry him.
Now do step 4 of the kata, the "reinforced block." Turn toward the swordsman and use your right hand to push the blade up the top of his right arm to his throat. The "block" slices the side of his neck. Even if he is wearing armor, slipping a blade under the edge of his helmet can still be a fatal attack. (See the essay on vulnerability of samurai armor for details.)
Like the opening of H. Nidan, the first four moves of H. Yondan show us how to take a sword away from a samurai, and then kill him with it.
