I think they refer to zahocho.
I had two iteration of toyama. One 210 migaki iron clad, sold (too short)... regretted it and bought a 240 Ku.
The migaki was from jns, and the Ku from zahocho.
Can't compared directly, of course the migaki had better f&f, but strictly on cutting performance, they are strictly equal.
Don't really understand why jns sell the same Ku for a lot more money (zahocho is maybe aggressive on pricing)...I doubt there is a significant difference in f&f that justifies the price gap...