Most(?) Japanese final finishing stones will leave hazy finish.(not include price above 2000 i have never tried them)
Some will do very good polishing job.
They are so much vary i don't think we could Generalize them.
It is normal for a J-Nat to show its true scratch pattern when used with water alone. As Stefan said some like Asagi are well known for this.
When used with slurry the particles breakdown & polish the scratches so they are reduced. Can't imagine why a totally clean dry stone ie no slurry remnants, would not also leave visible scratches.
They are pretty spongy, and I think that's why the surface effectively changes shape when wet, thus changing it's scratch pattern.
I heard that the Shaptons had spots that "swell" on them when the stones get wet and cause surface flatness problems. I assumed the same thing is happening on the Japanese stones, but on a particulate-scale.
Yeah, most of mine are not particularly absorbent, although I suppose I have never measured the wet/dry weight differential to actually find out.
I always had this theory, more a hypothesis really, actually a real stab in the dark.... When using my asagi I find water alone creates suction, kinda like when you lick a suction cap to make it stick. There's probably little in it, but I have observed the suction effect, almost like what you get on the Shapton glass stones.
James.
Good point James . Adding bicarb soda to the water increases that contact even more. A bit like the lather & barber hone trick.
That may explain why the dry stone scratches very little.