Japan is an island country, a string of islands on the eastern edge of Asia, and even the simple job of counting those islands has no single settled answer. According to a 2023 count, Japan is made up of about 14,125 islands, which was more than double the earlier count of 6,852 (as of November 2026). Taken as one piece of land, Japan, at 377,975 square kilometers, is a little larger than Germany, which is 357,596 square kilometers; Japan is about 6 percent bigger.
Yet that land is not easy ground to settle: about three-quarters of Japan's land is mountains or hills, so most people live on the flatter land that is left. Japan had 123.05 million people on October 1, 2025, according to the national census, and with about 338 people per square kilometer, measured in 2020, it is one of the most crowded countries among those with 10 million or more people (as of November 2026). About 30 percent of Japan's people, 37.0 million, live in the Tokyo area, which is Tokyo plus Kanagawa, Saitama and Chiba prefectures, so most Japanese people live elsewhere (as of November 2026).
The steep land has a cause deep underground. Around Japan, oceanic plates (the Pacific and Philippine Sea Plates) slide beneath continental plates (the North American and Eurasian Plates) several centimeters a year, which is why Japan has so much earthquake activity. When an oceanic plate sinks beneath a continental plate, the continental plate is dragged down and strain builds up; when the strain gets too big, the continental plate jumps up, and the tremors are called interplate earthquakes. Earthquake waves travel at two speeds: fast P-waves at about 7 km/s (25,200 km/h) and slower, more damaging S-waves at about 4 km/s (14,400 km/h). At a point 50 km from an earthquake's start, a P-wave arrives after about 7 seconds and the stronger S-wave after about 13 seconds, so places farther away get more warning time.
Measuring an earthquake takes two different ideas. Each 1-degree increase in earthquake magnitude means about 32 times more energy released by the earthquake, while Japan's shaking scale, the seismic intensity scale, has 10 degrees and describes how strong the ground motion is at one place. The Japan Meteorological Agency has about 600 seismic intensity meters around the country and collects data from another 3,600 stations, so shaking can be measured in many places (as of November 2026). Earthquake Early Warnings are issued slightly after a quake begins; they are not predictions that tell people an earthquake will happen in advance. Buildings face the same forces. Tokyo Skytree has a central pillar that works with a mass addition mechanism to calm shaking, and its makers say it can reduce the response shear force by about 40 percent during a major earthquake.
A tsunami starts when a big undersea earthquake makes the sea floor rise or sink; the water above moves up or down and the movement spreads out in all directions as waves. Tsunami waves slow down as the sea gets shallower, so the trailing waves catch up with those ahead near the coast and the tsunami grows much higher. To warn fast, Japan's weather agency simulates many possible undersea quakes ahead of time and stores the tsunami arrival times and heights in a database; after a big quake it matches the quake's location and size to the closest stored case. The land has fire as well as shaking. Mount Fuji sits about 110 km (70 miles) west-southwest of Tokyo in central Honshu, and its Hoei eruption happened on its southeastern slope on December 16, 1707.
The seasons bring other forces. Japan has two long rainy seasons, one in early summer when the southeast monsoon begins and one in autumn when the winds cease. In winter, cold air from Siberia flows over the warm Sea of Japan, and heavy snow falls on the Sea of Japan side of Honshu. Sapporo, on Hokkaido, typically has more than 140 days of snowfall and nearly 6 meters (20 feet) of snow in an average year (as of November 2026). The first Sapporo Snow Festival in 1950 drew about 50,000 people, a much larger crowd than expected, and by now the festival attracts more than two million visitors a year; the 2018 festival drew 2,543,000 people (as of November 2026).
The weather also sets the date of spring. Japan predicts cherry-blossom dates by applying the link between temperatures and bloom dates in past years to the temperatures measured since the previous fall and to weekly, monthly and three-month forecasts. The cherry blossom front starts in the south in late March and moves northward as the season goes on. The Japan Meteorological Agency says its predictions have a margin of error of two to three days each way.
Cherry trees have also become a thermometer. Kyoto's cherry-blossom records go back more than 1,200 years, the longest known data set of its kind, kept in diaries and chronicles. Scientists can use Kyoto's old flowering dates because they come from documents and diaries from the ninth to the fourteenth centuries. Researchers used cherry-blossom dates from old records to reconstruct a nearly continuous series of March mean temperatures, showing how plants can serve as an old thermometer. A 2022 study concluded that human-caused climate change is the main reason Kyoto's peak cherry bloom now comes earlier in spring (as of November 2026).
The wild animals of the north show how climate and land shape life. Japanese macaques, the snow monkeys, live farther north than any other primates in the world, and a study of snow monkeys found they used hot springs more often in the winter months. Kushiro-shitsugen in eastern Hokkaido is the largest marshland in Japan, covering 18,000 hectares. Japanese cranes were thought extinct around 1890 until a small group was found at Kushiro marsh; after locals began feeding them in 1952 the population recovered gradually, to more than 1,300 by the time of the Ministry of the Environment's pamphlet. The key threat to red-crowned cranes is the loss and degradation of wetlands in their breeding and wintering grounds.
People have lived in these islands for a very long time. The Jomon people of ancient Japan are named for their cord-marked pottery: the word Jomon means cord-marked. A diary entry shows that Murasaki Shikibu was writing The Tale of Genji in 1008, and the book is possibly the first novel in world literature. In 1603 the Tokugawa family began to rule Japan, and it ruled until 1868, a time called the Edo period. Ieyasu Tokugawa had the emperor appoint him shogun, and Tokyo was first called Edo; it began to flourish after Tokugawa Ieyasu set up the Tokugawa Shogunate there in 1603. For two centuries Japan limited trade access to Dutch and Chinese ships with special charters, so the rule of a single family and a narrow door to trade belong to the same long period.
Foreign ships arrived in the middle of the nineteenth century. In July 1853 American Commodore Matthew Perry brought his ships into Edo Bay, which is now called Tokyo Bay, and the Treaty of Kanagawa protected American sailors and opened two Japanese ports for refueling and resupply. The old Tokugawa class system of samurai, farmers, artisans and merchants was abolished by 1871. The Meiji period ran from 1868 to 1912, during which the Meiji Emperor reigned, and in it the capital moved from Kyoto to Edo, which was renamed Tokyo, meaning Eastern Capital. Japan's first railway began operating on October 14, 1872, and Emperor Meiji attended the opening ceremony at Shinbashi Station in Tokyo. Japan's school year starts in April because the Meiji-era government adopted a fiscal year running from April to March.
Government today rests on the 1946 constitution. Under it the Emperor is the symbol of the State and of the unity of the people, and performs only the acts in matters of state that the Constitution provides for. Japan's Diet is the highest organ of state power and the sole law-making organ of the State. In Japan the Prime Minister is designated from among the members of the Diet by a resolution of the Diet. Japan lowered its voting age from 20 to 18 under a law passed by the Diet in June 2015.
Writing in Japan came from outside and was then remade. Japan had no writing system, adopted Chinese characters, and later built the native scripts hiragana and katakana from them; kanji are descended from those Chinese characters. Hiragana are simple, cursive forms of whole kanji, while katakana are taken from parts of more complex kanji. The short haiku broke away from renga in the sixteenth century and was mastered a century later by the poet Matsuo Basho; haiku grew out of linked verse, and the first 5-7-5 part of a long renga was called a hokku. A newer kind of tiny writing began on Japanese mobile phones: emoji started as 176 characters, each 12 by 12 pixels, made by a Docomo employee for i-mode phones, and Emoji were added to Unicode 6.0 in 2010, which let them spread across many kinds of phones and computers.
Rice eaten per person fell from 118.3 kilograms a year in 1962 to 54.4 kilograms in 2016, less than half (as of November 2026). Japan's fish eating has fallen too: people ate about 21.4 kilograms of seafood a year each in 2023, down from a peak of 40.2 kilograms in 2001 (as of November 2026). Sushi does not simply mean raw fish: the word joins the words for vinegar and rice, and sushi is vinegared rice paired with a garnish of seafood, egg or vegetables, raw or cooked. The oldest kind, narezushi, was fish fermented with salt and rice; people first discarded the rice, and only later ate it with the fish.
The Tokaido Shinkansen bullet train has a top speed of 285 kilometers per hour (as of November 2026), and in fiscal 2023 its average delay was 1.6 minutes per train, including delays from natural disasters (as of November 2026). Japan had 56,054 convenience stores at the end of 2025, up by more than 300 during the year (as of November 2026).
The population is changing shape. Japanese women ranked first in the world for life expectancy for the 41st year in a row, as of the 2025 figures (as of November 2026). Japan had 671,236 babies born to Japanese nationals in 2025, a record low and 14,937 fewer than in 2024 (as of November 2026). As of September 1, 2025, Japan had 99,763 people aged 100 or older, about 88 percent of them women, and the number passed 100,000 for the first time, reaching 107,677 in September 2026 (as of November 2026).
Words to know
- monsoon: seasonal wind
- tsunami: sea wave
- shogun: military ruler
- katakana: Japanese script
- Diet: Japan's parliament
