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.
Korean currency
At the time of the introduction in 1945 the won was pegged to the Japanese yen at a rate of 1 won = 1 yen. In October of the same year the anchor currency got change to the US dollar at a rate of 15 won = 1 dollar. Toward the end of the Korean War the won was devaluated at 6000 won = 1 dollar. Following that the hwan was introduced as the new currency at a rate of 1 hwan = 100 won.