2020 coronavirus outbreak on cruise ships

Japan (日本, or, and formally 日本国, Nihonkoku) is an island country in East Asia. It is situated in the northwest Pacific Ocean and is bordered on the west by the Sea of Japan, extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans an archipelago of 6852 islands covering 377,975 km2; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa. Tokyo is the nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto.

Japan is the eleventh most populous country in the world, as well as one of the most densely populated and urbanized. About three-fourths of the country's terrain is mountainous, concentrating its population of 124.8 million on narrow coastal plains. Japan is divided into 47 administrative prefectures and eight traditional regions. The Greater Tokyo Area is the most populous metropolitan area in the world, with more than 37.2 million residents.

The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C., and its most populous city and principal financial center is New York City.

Indigenous peoples have inhabited the Americas for thousands of years. Beginning in 1607, British colonization led to the establishment of the Thirteen Colonies in what is now the Eastern United States. They quarreled with the British Crown over taxation and political representation, leading to the American Revolution and proceeding Revolutionary War. The United States declared independence on July 4, 1776, becoming the first nation-state founded on Enlightenment principles of unalienable natural rights, consent of the governed, and liberal democracy. The country began expanding across North America, spanning the continent by 1848. Sectional division surrounding slavery in the Southern United States led to the secession of the Confederate States of America, which fought the remaining states of the Union during the American Civil War (1861–1865). With the Union's victory and preservation, slavery was abolished nationally by the Thirteenth Amendment.