Japan (大日本帝國) is a sovereign state located in eastern Asia. It has one of the world's greatest economies, being third overall in GDP. As a predominantly island nation, the only two nations Japan borders are China and Manchuria, only because of their invasion of China during the 1940s.
Japan first appears in written history in the Chinese Book of Han. According to the Records of the Three Kingdoms, the most powerful kingdom on the archipelago during the 3rd century was called Yamataikoku. Buddhism was first introduced to the archipelago by Koreans from the Baekje kingdom, but the subsequent development of Japanese Buddhism was influenced by China. The Nara period started the emergence of a strong, isolated Japanese state, centered around an imperial court in modern Nara. It is characterized by its literature and architecture, as well as the devastating smallpox epidemic which killed as much as a third of Japan's population. In 784, Emperor Kammu moved the capital from Nara to Nagaoka-kyō before relocating it to Kyoto, marking the beginning of the Heian period. During this period of Japanese history, a distinctly indigenous Japanese culture emerged, notable for its art and literature. Murasaki Shikibu'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 two major sects; Tendai Buddhism and Pure Land Buddhism.
Japan's feudal era was most well-known for the rise of the samurai, a ruling class of warriors. This era also began the era of shoguns, feudal monarchs who proclaimed themselves emperor of Japan. The Zen school of Buddhism was introduced from China during the early feudal era as well; this sect quickly became popular with the samurai. The Kamakura shogunate is famous for its repelling of Mongol invasions in 1274 and 1281, though was eventually overthrown by Emperor Go-Daigo. During the 16th century, traders and Jesuit missionaries from Portugal arrived in Japan, initiating trade between Japan and the West. This allowed Japan to obtain European technologies and firearms, which shogun Oda Nobunaga used to conquer many surrounding shogunates. His son, Toyotomi Hideyoshi, unified the nation in 1590 and launched two unsuccessful campaigns against Korea in 1592 and 1597. The The Tokugawa shogunate was the first shogunate ruling over all of Japan. It initiated the isolationism which was enforced for the next two centuries, starting a period of political unity known as the Edo period. The study of Western sciences, known as rangaku, continued through contact with the Dutch enclave at Dejima in Nagasaki.
In 1854, the United States Navy forced Japan to open up to the outside world. Other treaties with western nations resulted in the resignation of the shogun, which in itself resulted to the Boshin War and the establishment of a centralized state nominally unified under the Emperor. Japan later turned to imperialism, engaging in wars against both China and Russia; the only successful one of these two was the Sino-Japanese War. early 20th century saw a brief period of "Taishō democracy" overshadowed by increasing expansionism and militarization. Japan continued its imperialism by invading and annexing the Manchu Empire and replacing it with a puppet state. Afterwards, Japan invaded eastern China, starting the Pacific War, in which they won. Most of Japan's colonies gained via this war would break away, however.