I guess anything's possible but if that's an Aoto he's honing on the wrong side & it's been cut wrong.
Unlike finishers you hone on the grain with Aoto.
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No, I mean if it was an Aoto you would need to hone on the narrow edge with the grain :)
If you guys are looking for aoto, check this out...its where I picked up some of mine...including a "blue":
Sharpening Stones, Woodworking Tools
None of my 3 aoto are cut like that...
In fact, looking at most of the aoto on the net, they have very little discernible grain; the only think I can tell is that along the broken corners of two of mine, there are faint crack-like lines running parallel to the finished surface.