After looking at pictures of a bunch of samurai helmets, I came to a realization that Darth Vader's helmet is more or less the shape of a samurai helmet. Maybe this should have been obvious to me (especially being a fan of the Hidden Fortress film), but it was a cool discovery for me.
George Lucas was inspired by samurai films. This film are called jidai seki (period films). From jidai --> jedi. Also C3PO and R2D2 are inspired by the couple of mongrels in Hidden Fortress.
A master of the more technologically advanced European saber would probably cut a Katana-wielding Samurai to ribbons. Good thing the Samurai would probably just shoot him from horseback anyway.