Amakusa is a city located in Kumamoto Prefecture, Japan. Amakusa City covers parts of two main islands, and six smaller islets. They are referred to as Kamishima and Shimoshima (Upper and lower island). It has the distinction of being the fastest depopulating city in Japan since the last census. (2005) The city was established on March 27, 2006, as a result of the merger between the old cities of Hondo and Ushibuka, and the towns of Amakusa (old), Ariake, Goshoura, Itsuwa, Kawaura, Kuratake, Shinwa and Sumoto, all from Amakusa District.