This is an exquisite antique Kutani porcelain coffee cup and saucer set, dating back over a century. It is a superb example of Hakutai (薄胎, or thin-walled porcelain), a rare type of Japanese pottery fired to such an extreme thinness that the intricate, hand-painted patterns become beautifully translucent when held up to the light. This piece is a testament to the masterful artistry and delicate technique of a craftsman from over 100 years ago.