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.
Economy of North Korea
In 1979, North Korea renegotiated much of its international debt, but in 1980 it defaulted on its loans except those from Japan. By the end of 1986, hard-currency debt had reached more than US$1 billion. It also owed nearly $2 billion to communist creditors, principally the Soviet Union. The Japanese declared North Korea in default. By 2000, taking into account penalties and accrued interest, North Korea's debt was estimated at $10–12 billion. By 2012, North Korea's external debt had grown to an estimated US$20 billion despite Russia reportedly writing off about $8 billion of debt in exchange for participation in natural resources development. Besides Russia, major creditors included Hungary, the Czech Republic and Iran.