Kosometsuke is a underglaze blue that was burned in jingdezhen-kiln around the tenkei （1621～27） years of the ming dynasty.
Especially known as a work for japan.
It is roughly divided into tea utensils and daily necessities that are custom-made items from japanese tea people.
The category of tea utensils is thick in general.
At the end of the ming dynasty, japanese tea people actively ordered tea utensils.
Most of the works have peeling at the edge due to the difference in shrinkage between the substrate and glaze.
This phenomenon is called “mushikui” because it looks as if a bug has crawled.
Usually it is a drawback, but japanese tea people rated it as an aesthetic effect.