Japan

Nozomi Shinkansen or 'Bullet train' at Tokyo Station

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 that 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. 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 over 127 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 economic power, 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 peacekeeping roles. It is a developed country with very high living standards (10th highest HDI). Japan has the highest life expectancy of any country in the world (according to both the UN and WHO estimates) and the third lowest infant mortality rate.

Cherry blossoms in Kichijoji, Tokyo

The "Land of the Rising Sun" is a country where the past meets the future. Japanese culture stretches back millennia, yet has also adopted (and created) the latest modern fashions and trends.
Japan is a study in contrasts and contradictions. Many Japanese corporations dominate their industries, yet if you read the financial news it seems like Japan is practically bankrupt. Cities are as modern and high tech as anywhere else, but tumbledown wooden shacks can still be spotted next to glass fronted designer condominiums. On an average subway ride, you might see childishly cute character toys and incredibly violent pornography - sometimes enjoyed by the same passenger, at the same time! Japan has beautiful temples and gardens which are often surrounded by garish signs and ugly buildings. In the middle of a modern skyscraper you might discover a sliding wooden door which leads to a traditional chamber with tatami mats, calligraphy, and tea ceremony. These juxtapositions mean you may often be surprised and rarely bored by your travels in Japan.

Climate
The Japanese are proud of their four seasons (and an astonishing number of them are firmly convinced that the phenomenon is unique to Japan), but the tourist with a flexible travel schedule should aim for spring or autumn.
Spring is one of the best times of year to be in Japan. The temperatures are warm but not hot, there's not too much rain, and March-April brings the justly famous cherry blossoms (sakura) and is a time of revelry and festivals.
Summer starts with a dreary rainy season (known as tsuyu or baiu) in June and turns into a steambath in July-August, with extreme humidity and the temperature heading as high as 40°C. Avoid, or head to northern Hokkaido or the mountains of Chubu and Tohoku to escape. The upside, though, is a slew of fireworks shows (花火大会 hanabi taikai) and festivals big and small.
Autumn, starting in September, is also an excellent time to be in Japan. Temperatures and humidity become more tolerable, fair days are common and fall colors can be just as impressive as cherry blossoms. However, in early autumn typhoons often hit the southern parts of Japan and bring everything to a standstill.
Winter is a good time to go skiing or hot-spring hopping, but as some buildings lack central heating, it's often miserably cold indoors. Heading south to Okinawa provides some relief. There is usually heavy snow in Hokkaido and northeast Japan due to the cold wind blasts from Siberia. Note that the Pacific coast of Honshu (where most major cities are located) has milder winters than the Sea of Japan coast: it may be snowing in Kyoto while it is cloudy or sprinkling rain in Osaka, an hour away.