vintage Japan stoneware pottery cups & saucers, traditional Arita fan pattern all in blue

1970s or 80s vintage Japan ceramic cups and saucers, a set for four. The pattern looks like Arita - Imari fan, but all in a single shade of blue, rather than the multi colored Imari design. The cobalt blue on the tan speckled stoneware is unusual and lovely!

There's no makers marks on any of these pieces, I expect they were marked with foil labels originally. All are in very good condition, no chips, staining or any noticeable wear.

The saucers measure 5 1/2" in diameter. Cups are 2 3/4" tall, maybe demitasse or espresso cups? Or small teacups.