Korean yen
The Korean yen was the currency of Korea between 1910 and 1945. It was equivalent to the Japanese yen and consisted of Japanese currency and banknotes issued specifically for Korea. The yen was subdivided into 100 sen. It replaced the Korean won at par and was replaced by the South Korean won and the North Korean won at par.
Dandong
A substantial portion of North Korea's international trade, both legal and illegal, passes through Dandong and Sinuiju, across the Yalu River in North Korea. China handles roughly 40% of North Korea's worldwide export trade ($1.58 of 4 billion USD) and roughly half of the bilateral commerce with China goes through Dandong which imports $468 million [USD worth of product], according to its Ministry of Commerce. Dandong's annual resident per capita wage income for 2004 was somewhere between ¥9,500 and ¥12,237 RMB and the city's GDP was 3.77 billion USD.