Amazonas (Brazil) is 4.2 times larger than Japan.
Area: 377,915 km2 World Factbook
Population: 127,103,388 (July 2014) World Factbook
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. Wikipedia
Amazonas is a state of Brazil, located in the northwestern corner of the country. It is the largest Brazilian State by area and the 9th largest country subdivision in the world. Neighbouring states are Roraima, Pará, Mato Grosso, Rondônia, and Acre. It also borders Peru, Colombia and Venezuela. Wikipedia