Query: Japan is represented by one centralized federal government.

Relevant passages:
Japan <=SEP=> Japan ( 日本 Nippon -LSB- ɲip̚poɴ -RSB- or Nihon -LSB- ɲihoɴ -RSB- formally or Nihon-koku , meaning `` State of Japan '' ) is a sovereign island nation in East Asia . Located in the Pacific Ocean , it lies off the eastern coast of the Asian mainland , and stretches from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the southwest .   The kanji that make up Japan 's name mean `` sun origin '' . 日 can be read as ni and means sun , while 本 can be read as hon , or pon and means origin . Japan is often referred to by the famous epithet `` Land of the Rising Sun '' in reference to its Japanese name .   Japan is a stratovolcanic archipelago consisting of about 6,852 islands . The four largest are Honshu , Hokkaido , Kyushu and Shikoku , which make up about ninety-seven percent of Japan 's land area and often are referred to as home islands . The country is divided into 47 prefectures in eight regions ; Hokkaido being the northernmost prefecture and Okinawa being the southernmost one . The population of 127 million is the world 's tenth largest . Japanese people make up 98.5 % of Japan 's total population . Approximately 9.1 million people live in the city of Tokyo , the capital of Japan .   Archaeological research indicates that Japan was inhabited as early as the Upper Paleolithic period . The first written mention of Japan is in Chinese history texts from the 1st century AD . Influence from other regions , mainly China , followed by periods of isolation , particularly from Western Europe , has characterized Japan 's history . From the 12th century until 1868 , Japan was ruled by successive feudal military shoguns who ruled in the name of the Emperor .   Japan entered into a long period of isolation in the early 17th century , which was ended in 1853 when a United States fleet pressured Japan to open to the West . After nearly two decades of internal conflict and insurrection , the Imperial Court regained its political power in 1868 through the help of several clans from Chōshū and Satsuma , and the Empire of Japan was established . In the late 19th and early 20th centuries , victories in the First Sino-Japanese War , the Russo-Japanese War and World War I allowed Japan to expand its empire during a period of increasing militarism .   The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941 , which came to an end in 1945 following the atomic bombings of Hiroshima and Nagasaki and the Japanese surrender . Since adopting its revised constitution on May 3 , 1947 during the occupation by the SCAP , Japan has maintained a unitary parliamentary constitutional monarchy with an Emperor and an elected legislature called the National Diet .   Japan is a member of the UN , the OECD , the G7 , the G8 , and the G20 and is considered a great power . The country has the world 's third-largest economy by nominal GDP and the world 's fourth-largest economy by purchasing power parity . It is also the world 's fourth-largest exporter and fourth-largest importer . The country benefits from a highly skilled workforce and is among the most highly educated countries in the world , with one of the highest percentages of its citizens holding a tertiary education degree .   Although Japan has officially renounced its right to declare war , it maintains a modern military with the world 's eighth-largest military budget , used for self-defense and peacekeeping roles . Japan is a developed country with a very high standard of living and Human Development Index . Its population enjoys the highest life expectancy and the third lowest infant mortality rate in the world .

Sovereign state <=SEP=> A sovereign state is , in international law , a nonphysical juridical entity that is represented by one centralized government that has sovereignty over a geographic area . International law defines sovereign states as having a permanent population , defined territory , one government , and the capacity to enter into relations with other sovereign states . It is also normally understood that a sovereign state is neither dependent on nor subjected to any other power or state .   The existence or disappearance of a state is a question of fact . While according to the declarative theory of statehood , a sovereign state can exist without being recognised by other sovereign states , unrecognised states will often find it hard to exercise full treaty-making powers and engage in diplomatic relations with other sovereign states .