Artificial Chu-nagura stone.
4th stone of the groundwork, used before Koma-nagura-do.
By Chu-nagura, the mark of Kaisei must be removed.
This artificial stone is a little harder than the natural Chu-nagura.
It can distinguish the mark of Kaisei very well.
If you get this stone you will be able to work efficiently.
Dimensions : 20 x 5 x 5cm
Weight : 1kg
