These are the first official(issued by Japan mint) bimetallic commemorative coin in Japan. 47 types will be issued. 47 means the number of prefecture. In 2008, Hokkaido, Kyoto and Shimane were issued at the same time. In 2009, 2 coins (Nagano and Niigata) were issued. In 2010, Ibaraki and Nara were issued.