Japan Business Directory: JPN is the ISO 3 alphabet country code of Japan. Currency of Japan is ¥, which has a short code of JPY. Capital of Japan is Tokyo. Japan has the population of 127185332 and approximate area is 377915.00 square kilometers (or approx. 234836.381 square miles). Population density of Japan is approx. 336/Km2 (or approx. 208.7904/mile2)