Japan, Tokugawa Shogunate, early Kaei Era, no date, 1853-1865 AD.,
Shu (or Isshu Gin) (10 x 15 mm / 1,91 g),
Obv.: Ichi / Shu / Gin , three lines Japanese characters, translated: "one / Shu / silver" .
Rev.: tei / Ginza / Joze , "tei" punchmark (controlmark for the specified weight) and two lines Japanese characters, translated: "specified weight / silver coin and national silver mint / Joze" (-family name (Daikokujotze?), probably the clan initially responsible for the production of this coin type).
C 12 ; http://www.numismatik-cafe.at/viewtopic.php?f=6&t=3094 .