I am not sure what it is, but it is certainly trying to look Japanese. I found something similar here:
http://cgi.ebay.com/ws/eBayISAPI.dll...253D&viewitem=
The Tokugawa mon is actually what made me think it was Chinese. I thought such a mon would be restricted to clan members within Japan but would be something that a Chinese copier might pick as a showy motif. Also the mon forms two sides of the metal peg that holds the tang in place and there is no way that I can figure out to disassemble the sword in the Japanese manner. The only way to disassemble the blade would be to destroy the emblem. Would someone Japanese make a sword that way? I think I can leave out the Korean possibility because the style is too perfectly Japanese, but I still wonder if it was not made in China for export.
I do agree that the engraving is much deeper than that found on Chinese blades, and what appears to be the hamon is very straight and even, something I have never seen on a Chinese blade.
Either way, I am very happy with it because it is beautiful and I got it for a Chinese sword price
Josh