I have never purchased/used any from the KK series but had/have been using several from the KS, HS and HA series. Knives from KK series I believe is shiroko kasumi and has a hardness of 62 - 63.
I am of the opinion that the finish (choil, spine etc) on the Masamoto knives is average only, certainly not their strength (I am comparing it to the Nenohi knives which I own also).
The grind, however, is excellent in most of the Masamoto knives that I own, especially those from HS and HA series. Note that in all Masamoto knives, it tapers in at the heel. It is not a grind issue and I've learned to keep the profile when I sharpen and not grind it flat.
I am a big fan of Masamoto single bevel knives as it works so well.
