It is this coin that a digger from Seattle found. It is a very common 18th century Kanei Tsuho.
1862 Akita 100 Mon ... Really??
Found this on eBay.
Seller writes: ND 1862 Akita, Japan 100 Mon Cast Lead KM#8
Up for sale is a pre-Meiji Restoration lead coin, face value 100 Mon. It is a small rectangular plate that measures 1 1/2 inches long by 1 3/16 inches wide by 1/16 inch thick. It is an ideal piece for collectors of Japanese numismatics from that era.
Someone paid $20 for it. It looks nothing like the real thing! Would you pay $20 for a large pizza with everything on it that is made of cardboard?