The word Japan is an exonym and is used (in one form or another) in many languages. The Japanese names for Japan are Nihon and Nippon. Both Nippon and Nihon literally mean "the sun's origin", that is, where the sun originates, and are often translated as the Land of the Rising Sun. This nomenclature comes from Imperial correspondence with the Chinese Sui Dynasty and refers to Japan's eastern position relative to China. Before Nihon came into official use, Japan was known as Wa or Wakoku. Wa was a name early China used to refer to an ethnic group living in Japan around the time of the Three Kingdoms Period. The Yayoi people primarily lived on the island of Kyushu to the Kanto region on Honshu.

Source: Wikipedia