This is disturbingly good, I especially liked how the six coins motif was worked in, though I have to wonder, was it the six circles on the sheath, or the six dots on the blade, or both, that was supposed to be the defining mark of the six coins.
Not to mention, of course, the six circles you get on it when it's fully sheathed from the Scabbard, Tsuka, and Shitodome Kanagu. To be honest, I'm actually more surprised that you chose the circle (at least, I think it goes around in a circle) of (I count 7) rectangles for the Tsuba, as opposed to another drop of the 'six coins' theme.
Very cool, nice to see someone who knows the construction of a katana draw a picture of ones components.
The picture itself is superbly detailed I find, the edge is clear and visibly sharp, whilst having the right amount of sheen on it. The nagako's detail in particular appeals to me, gritty and rough as I would expect it to be.
The saya looks, quite frankly, stunning, the wood effect is really vivid and polished (as it were). Whilst the design on it's side, and the kurigata, are both well drawn and fitting to the piece. Incidentally, curious design for the tsuba, though I can't help but feel you might cut or scratch your hand on it somewhat haha