Japan (日本, Nihon or Nippon?, officially 日本国 Nippon-koku or Nihon-koku) is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters which make up Japan's name mean "sun-origin", which is why Japan is sometimes referred to as the "Land of the Rising Sun". Japan is an archipelago of 6,852 islands.[9] The four largest islands are Honshū, Hokkaidō, Kyūshū and Shikoku, together accounting for 97% of Japan's land area. Most of the islands are mountainous, many volcanic; for example, Japan’s highest peak, Mount Fuji, is a volcano. Japan has the world's tenth-largest population, with about 128 million people. The Greater Tokyo Area, which includes the de facto capital city of Tokyo and several surrounding prefectures, is the largest metropolitan area in the world, with over 30 million residents. Archaeological research indicates that people were living on the islands of Japan as early as the Upper Paleolithic period. The first written mention of Japan begins with brief appearances in Chinese history texts from the first century A.D. Influence from the outside world followed by long periods of isolation has characterized Japan's history. Since adopting its constitution in 1947, Japan has maintained a unitary constitutional monarchy with an emperor and an elected parliament called the Diet. A major power,[10] Japan has the world's second-largest economy by nominal GDP and the third largest in purchasing power parity. It is also the world's fourth largest exporter and fifth largest importer. It is also the only Asian country in the G8 and is currently serving as a non-permanent member of the UN Security Council. Although Japan has officially renounced its right to declare war, it maintains a modern and extensive military force which is employed in self-defense and