May 11, 1998
Obverse: Japanese inscription ? Kan Tsu Ho|
Diameter: 22.6 mm
Weight: 2.9 g
In some books this coin mentioned as Japanese, issued in 1875. But background is uncleared for me.
Message from Martin Purdy, 13-May-98:
Message from Dr.Yih, 17-Sep-98:
On the reverse side on top of the hole is the character AN. This is for the designation of the AN SEI reign period (1854-59) of the KOMEI emperor.
The piece is mentioned also to exist with an octagonal instead of a round central hole.
Chinese Coinage Web Site