Cash coins were introduced to Japan in the century inspired by the Chinese Kaigen Tsūhō (開元通寳) cash coins from the Tang dynasty. Chinese cash coins also circulated in other countries and inspired similar currencies such as the Korean mun, Ryukyuan mon, Vietnamese văn, while they also circulated as far south as Indonesia. Because these currencies were so similar cash coins around the Far East were interchangeable and Japanese cash coins circulated in other countries while foreign cash coins also circulated in Japan.