These are not specifically dated and were made from around 1739 all the way up to the Meiji ascension in 1867.
The Japanese started coining again during the 17th century after a break of several hundred years when they just imported coins from China(sound familiar?) Beginning in the 17th century with the Dutch, British etc starting to enter the neighbourhood the Japanese started to wind down on all foreign trade as a perceived threat to Japanese sovereignty. The Dutch were permitted one small trading post - but otherwise there was practically no foreign trade at all until Commodore Perry entered Tokyo Bay in 1854 and the Shogunate agreed to open up diplomatic missions and foreign trade, albeit under the barrel of the guns of US warships. By the mid 19th century Japanese coinage was quite fascinating for modern collectors, but very archaic in practicality. Their early decimal coinage in the 1870s was modeled on US coinage - as was their earliest Yen denominated paper money. But as previously noted the earlier coinage, or money as it may be, is quite fascinating, what with square coins, bean shaped coins, large oval 100 mon coins, and the gold obans and kobans.
