Kumamoto (kōmäˈmōtō) [key], city (1990 pop. 579,306), capital of Kumamoto prefecture, W Kyushu, Japan. It was an important castle town in the 17th cent.; one of its castles (built 1651) still stands. There are also several shrines in the city. Kumamoto prefecture (1990 pop. 1,840,383), 2,872 sq mi (7,438 sq km), is noted for the Aso-san volcanic peaks and for its many islands. With a predominantly agricultural economy, Kumamoto has such crops as rice, silk, and tobacco. Forestry and fishing are also important, along with such industries as textiles, processed foods, chemicals, and paper.