Kohiki glaze style - Japanese pottery
Kohiki is a style of glazing in pottery, where white glaze is applied on top of the black glaze, then translucent glaze on the top. This syle of glazing is said to have come from Korean Peninsula to Japan around 16th Century.
The name "kohiki" comes from the fact that it is white as if you put powder on the pottery. It has a warm white color, that is popular by many people who use handmade pottery in daily life.
Kohiki pottery absorbs some liquid, which is usually gone, but occassionally it might stay. That is also a characteristics you could enjoy as it becomes your only one plate/cup/bowl etc.
In some cases, you can also find other color Kohiki pottery such as this grey pot & cup (above photo).