Sousen/Origin

宋銭 ／ literally, “Song [Sung] coins”

Copper coins minted in China during the Song dynasty (960−1279). After the last minting of Japanese coins (kōchō jūnisen) in 958, coins imported from China and Korea were used in increasing numbers. Sōsen circulated widely in Japan as a result of trade in East Asia in the 13th century. With kōbusen and eirakusen−both coins of the Ming dynasty (1368−1644)−sōsen were the major currency until coins were once again minted in Japan by Oda Nobunaga and Toyotomi Hideyoshi. These coins stimulated the money economy because they were sometimes used in place of rice for paying taxes.