Shobu Tomo Nagura Japanese Natural Sharpening Stone ( hard and finest class stone in the fine grit stones) 138g (3oz)
45mmX45mmX23mm #6000 to #10000 Grit
This small Shobu whetstone is for Tomo Nagura. Tomo means the same kind of or sharing in Japanese.
Tomo Nagura means what the both base whetstone on the bottom side and the rubbing side of whetstone on the top side are the same kind of whetstone, and rubbing each other to produce slurry. Some of Shobu Asagi or Aisa whetstones are hard, and it is sometimes hard to get slurry at the beginning of sharpening.
It produces slurry while the sharpening the blade or protects the blade sharpening without slurry as buffer.
With sharpening with not enough amount of slurry, the whetstone might make scratching on the blade.
There are over 30 of mines in Kyoto, but there are not too many razor quality hard and fine particles whetstones mines. Nakayama, Ozuku, and Wakasa are a few of mines that produce razor sharpening quality whetstones. Shobu also has very hard and very fine grit razor quality whetstone.
Umegahata area used to produce great finishing whetstones too.