Tree peony obidome with Toshikane (俊兼) signature.
Obidome is a piece of jewelry for decorating obi, or a sash, on women’s Japanese kimono. (Button Country website as a nice description on obidome.) In the National Button Society Classification, obidome is categorized in the Division IV, Related Specialties.
The WRBA Nov. 2016 Newsletter has an article on two men from the Arita area of Japan who founded the Toshikane company in the 1930s.
(images courtesy of Luana, K.K..)