Yeah, I have no idea how the Japanese engaged in close in armored fighting. I **think** they stayed at distance and fought around the armor. This comes from a demonstration that I saw. It was not clear to me if this was entirely how they fought, but as mentioned, they targeted eye slits, palms, various straps and so forth. I do know they closed in for wrestling, which generally results in daggers being deployed and the usual Ju Jitsu fun.
A few notes: first, battlefield injuries came primarily from other weapons, because troops attempted to avoid closing to sword distance. Analysis of bodies from several Japanese battlefields in the medieval era showed that things like arrows and (held, not thrown, of course) spears, and even rocks, killed more people than swords on the battlefield. Next, whatever is shown in demonstrations,
if you have a sword or an even longer weapon, you're not going to attempt to close to wrestling distance. This is what my instructor describes as "dojo syndrome", doing something in training you would never do in real life.
If I have a longer weapon like a spear, I'm going to attempt to keep a swordsman outside his effective range, and he will attempt to close to his effective range. What's
not going to happen, is that swordsman getting close to me, then dropping his sword and trying to use an even shorter ranged weapon. What could realistically happen, though, is samurai grabbing for a tanto or shoto if they ended up getting "locked up" with another samurai. In that case, that wouldn't have been a deliberate choice, it's just how the battle ended up working out. It's rather like the compact fighting knife that Sam and I are still working on. It's not meant to be a primary or even secondary weapon, it's a tertiary weapon to use if you end up finding yourself fighting with an enemy at close range. The engagement wasn't
designed to end in grappling, it's just where you found yourself through weapons malfunction or other happenstance. My own
current instructor found himself grappling with an enemy combatant while the instructor was wearing armor on at least one occasion.
Oddly enough, many of the old Japanese targets are viable once more, as body armor is becoming commonplace on the battlefield again. For a couple of hundred years, targeting the armpit, for example, didn't make much sense when there is the entire upper chest area to attack. Now, it might make sense again (since the upper chest area will usually have the most armor) You're probably not going to stalk an enemy on the battlefield, close to contact distance, and stab him in the armpit. You might, however end up at close range, and if you can't shoot him, that target could eventually present itself. Rare, but possible.
What we in the west tend to forget, is that swords weren't primary weapons on the Japanese battlefield. They were analogous to handguns for troops today. You wanted to stop the enemy with a ranged weapon, if unable to do that, you wanted to stop him at the longest range possible. The movies we're used to seeing of samurai swaggering around wearing their sword sets came from times of relative peace in Japan. The revolver might be one of the few symbols we associate with cowboys, but it certainly wasn't the tool he used the most.
John