Taiwan, officially the Republic of China (ROC), is a country in East Asia. Neighbouring countries include the People's Republic of China to the northwest, Japan to the northeast, and the Philippines to the south. The main island of Taiwan has an area of 35,808 square kilometres (13,826 sq mi), with mountain ranges dominating the eastern two-thirds and plains in the western third, where its highly urbanised population is concentrated.

Japan is an island country in East Asia located in the northwest Pacific Ocean. It is bordered by the Sea of Japan to the west and extends from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. Part of the Pacific Ring of Fire, Japan comprises an archipelago of 6852 islands covering 377,975 square kilometers (145,937 sq mi); the country's five main islands, from north to south, are Hokkaido, Honshu, Shikoku, Kyushu, and Okinawa.