For a Japanese knife, get a smooth steel, and it is not for sharpening at all. It is just for adjusting the edge. All you need is a couple of light swipe along each side of the edge before cutting. And for gawds sake, do not slap it on the steel like you see on t.v., just a smooth delicate swipe or two is all it takes.
Never us a grinder or belt sander. That stone will be all you need, unless you just want to be fancy.
Whip It Off, Chambers!
"perhaps...but then again...maybe not..."