Lonely Planet, in the introduction of their travel guide on Japan, sum the country up well:
Japan is a world apart – a cultural Galápagos where a unique civilization blossomed, and thrives today in delicious contrasts of traditional and modern. The Japanese spirit is strong, warm and incredibly welcoming.
Japan is an island nation in the northeast of Asia. It has four major islands, Honshu, Shikoku, Kyushu, and Hokkaido, in addition to scattered island chains. It covers an area of approximately 378,000 sq. km. Owing to its long north-south extent of 3,000 km, there are significant regional differences in climate and distinctive seasonal transitions.
Japan is blessed with many sightseeing areas that offer beautiful natural scenery and landscapes. Many of the traditions that make up Japan's unique cultural heritage, such as performing arts and architecture cultivated by its long history, are also well worth seeing. Additionally, festivals held around the country and regional characteristics formed by the differences in climate are also fascinating and will help you better understand Japan.
Japan is an enthralling country, with a blend of development, seen in cities such as Tokyo, natural beauty, as seen in the natural environment that abounds in this island nation, and diverse regions bound together with a unique cultural heritage.
A major economic power, Japan has the world's third-largest economy by nominal GDP and fourth-largest economy by purchasing power parity. It is also the world's fourth-largest exporter and fourth-largest importer. Although Japan has officially renounced its right to declare war, it maintains a modern military with the sixth-largest military budget, used for self-defense and peacekeeping roles. After Singapore, Japan has the lowest homicide rate, including attempted homicide, in the world. According to Japan's Ministry of Health, Japanese women have the second highest life expectancy of any country in the world. According to the United Nations, Japan also has the third-lowest infant mortality rate.