But the Koma is irreverent to a good edge, the Tomo is used at the final stage, after the Koma.
I've got the full set of Mikawa naguras, Botan, Mejiro, Tenjio and Koma, I use them just for fun.
You get the same edge honing on synthetics up to 15-20K and then use the Tomo on a good Jnat.