Four Chinese characters (read clockwise) - Ki Nei Gen Ho (Japanese reading) / Blank. 24mm, 2.43 grams. Issued 1668-1685. Hartill (Japan) 3.193.
These coins were cast in the 17th century in Nagasaki to facilitate trade between Japan and Vietnam. Japan was exchanging silver and copper for raw silk, sugar, spices and sandalwood. After several requests and denials, on the 14th day of the 7th month of the 2nd year of Manji (1659) the Tokugawa Shogunate gave permission to Nagasaki to cast coins, and they continued to do so until 1685. These coins are known as Nagasaki Trade Coins (長崎貿易銭 Nagasaki Boeki-sen), and circulated in Vietnam along with the small coins minted locally. The trade must have been profitable for the Japanese, for it is recorded that a string of cash worth 1 liang of silver in Japan was priced at 10.5 liang in Vietnam. The inscriptions on these coins were derived from those of the Chinese Song Dynasty (960-1127).