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.
North Korean won
On July 25, 2014, a new 5,000 won note dated 2013 was released into circulation. Instead of depicting the portrait of North Korea's founder Kim Il-sung, the note depicts an image of his birthplace in Mangyondae and on the back the International Friendship Exhibition in Myohyangsan that displays gifts he and his son Kim Jong-il received from foreign leaders. There has been ongoing speculation that this could indicate plans for higher denominations to be released later which would depict Kim Il-sung, Kim Jong-il, or possibly both. However the official reason behind the change was to combat counterfeiters.