bulstuff
Katanas are just over-glorified razor blades that are completely ineffective against almost all types of European armor, A katana cannot stab through or cut through chainmail or plate at all. But you know what can? A bastard sword, because when it comes to armor entry, the inertia and blunt force of a weapon is just as important as important as its sharpness. Which is why against anybody but an unarmored opponent, a heavy, thick blade will always beat out a light, sharp one.
In actual combat, the Samurai carried their swords as status symbols only, and preferred to fight with either the naginata or the doushin; both weapons with adequate armor entry and much more suited to combat than the katana.
Besides, a medieval knight would totally kick a samurai's ass.
