Japanese yunomi, Bizen or Tanba ware

I think that it is meant to look like Bizen ware but it's not. Wrong clay.

The white specks in this beaker are probably quartz and/or felspar, which are characteristic of Shigaraki clay and are not present in Bizen clay. However, I suspect this clay has had the minerals added in much the same way as some British wood-firers add them.

Without seeing a pot it's very difficult to be certain but I suspect this is factory made and might not have been wood-fired, just simulated to look as if it has.

In my opinion the shape isn't really right for Bizen, Shigaraki or Iga.

It could have been made in Tamba (or Tanba - both spellings seem to be used these days) or Shigaraki but I don't think by an individual potter or in a studio pottery type kiln.