Japan is an archipelago of 6,852 islands. The four largest islands are Honshū, Hokkaidō, Kyūshū and Shikoku, together accounting for ninety-seven percent of Japan's land area. 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.
A Paleolithic culture around 30,000 BC constitutes the first known habitation of Japan. This was followed from around 14,000 BC by a Mesolithic to Neolithic semi-sedentary hunter-gatherer culture, who include ancestors of both the contemporary Ainu people and Yamato people, characterized by pit dwelling and rudimentary agriculture. Decorated clay vessels from this period are some of the oldest surviving examples of pottery in the world. Around 300 BC, the Yayoi people began to enter the Japanese islands, intermingling with the Jōmon. The Yayoi period, starting around 500 BC, saw the introduction of practices like wet-rice farming, a new style of pottery, and metallurgy, introduced from China and Korea.
The Japanese first appear in written history in the Chinese Book of Han. According to the Records of Three Kingdoms, the most powerful kingdom on the archipelago during the 3rd century was called Yamataikoku. Buddhism was first introduced to Japan from Baekje, but the subsequent development of Japanese Buddhism was primarily influenced by China. Despite early resistance, Buddhism was promoted by the ruling class and gained widespread acceptance beginning in the Asuka period.
The Nara period of the 8th century marked the emergence of a strong Japanese state, centered on an imperial court in Heijō-kyō. The Nara period is characterized by the appearance of a nascent literature as well as the development of Buddhist-inspired art and architecture. The smallpox epidemic of 735–737 is believed to have killed as much as one-third of Japan's population. In 784, Emperor Kammu moved the capital from Nara to Nagaoka-kyō before relocating it to Heian-kyō in 794.
Byōdō-in is a temple of Pure Land Buddhism. It was registered to the UNESCO World Heritage Site.
This marked the beginning of the Heian period, during which a distinctly indigenous Japanese culture emerged, noted for its art, poetry and prose. Lady Murasaki's The Tale of Genji and the lyrics of Japan's national anthem Kimigayo were written during this time.
Buddhism began to spread during the Heian era through chiefly two major sect, Tendai by Saichō, and Shingon by Kūkai. Pure Land Buddhism greatly becomes popular in the latter half of the 11th century.