Hello,
My grandfather was in Japan in WW2 and was sold a sword by a local, he bought the sword, his buddy bought a Namboo Pistol. My grandfather after returning to California from the war disassembled the sword and seems to have lost all but the blade. We are still searching trough boxes looking for the handle and such. I have attached pictures of the marking on the tang. It does not seem to be WW2 era and my grandfather thinks he remembers something about edo period being mentioned. My grandfather has since died but my grandmother want to know more about it and was recommended to this forum by a member, Dr. Les Dorfman. Thanks you for any input