I believe this is contemporary now as well after having shared it with another collector on the side. Whether its Korean or Japanese studio, my gut says its Korean given the upper-band decoration concept and the overall shape being influenced by buncheong brush washers. There is a slight border on the upper side under the lip which supports Buncheong conceptual designs, but I doubt this was a half-join style given the perfection of the sides. Maybe Korean influence to japanese markets is possible. Shame its not signed. 

I don't know much about these wares, but in the course of researching, I came across this interesting video which some of you may enjoy:

https://www.facebook.com/NationalMuseumofKorea.eng/videos/buncheong-ware-in-underglaze-iron/595803291534646/

This came in over the weekend. Very happy with this piece, and I believe it could be joseon buncheong. The texture, styling and condition at least suggest its period. Although I have not handled a period piece yet aside from a contemporary recreation. This one is unsigned as well giving me some hope. I have come across this form being described as a brush washer, but these are generally smaller (half the size) of this one. 

Its around 8x10 inches. 

Any insight is appreciated.