Well Made Porcelain Yunomi or Beaker Unmarked

Another item for the job lot I picked up last week. This is a sweet, very tactile beaker or yunomi, I love the form and made from porcelain which should hopefully narrow down the search. There appears to be copper in the glaze, particularly on the rim and interior although this may not be so apparent in the photos, the metallic sheen sometimes looks much more matt in pictures. It measures 9.4cm in height by 8.9cm.

Thanks in advance.