Japan is 5,385 times larger than Bayamón, Puerto Rico.
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
Area: 70 km2 calculated
Bayamón, commonly known as BayaBronx, is a municipality of Puerto Rico located on the northern coastal valley, north of Aguas Buenas and Comerío; south of Toa Baja and Cataño; west of Guaynabo; and east of Toa Alta and Naranjito. Wikipedia