Whatislove said:
When you said your Katana is historical length is the exact point at which it wasn't a fair comparison.
The average length of a Katana blade, historically speaking, was actually 23" but this is because a Katana should be tailored to your personal height... people were short in feudal Japan.
I am 6"3 and my Katana's have a blade length of 33"
Also, as someone already mentioned in this thread, if we are talking 2 historically accurate swordsman, the samurai armour would almost entirely negate the rapier.
We would also have to look at build quality of the 2 blades, it is more than likely that any well made katana could cleave a rapier's blade in half with relative ease.
It is really almost impossible to say who would come out on top because there are so many variables, an infinite number of scenarios and arguments could be made for each winning this duel.
The ideal rapier length is from the ground to your belly button, which for you would be much longer than the average 40 inches (which is much longer than your katana). Any way you look at it the katana is easily outmatched in length by Viking broadswords, let alone a rapier.
Japanese armor has a lot of neat little gaps, like the armpits, the face, etc. European duelists would be used to going against armor much much better than the lamellar the Japanese had (full plate weighs 6-70 lbs, is fitted and articulated to the individual, it doesn't hinder the man's movement). They would likely be carrying a dagger as well, and in some periods that dagger was a very strong spike meant to punch through the heaviest of armors. This combined with grappling techniques and familiarity with opponents using weapons similar to a katana (which is just a 2 handed sabre with a short blade) would give advantages over the samurai.
The katana was made using folded steel over an iron core, something the Pre-Roman Celts were doing about 2 THOUSAND years before. The rapier is made of an advanced and well tempered monosteel that the Japanese couldn't match. The rapier faced off against the longsword and had very little trouble in dealing with the strikes from that. I wouldn't worry even the slightest about my rapier being broken by a Japanese sword.