The Kantō region (関東地方, Kantō-chihō) is a geographical area of Honshu, the largest island of Japan. The region includes the Greater Tokyo Area and encompasses seven prefectures: Gunma, Tochigi, Ibaraki, Saitama, Tokyo, Chiba, and Kanagawa. Within its boundaries, slightly more than 45 percent of the land area is the Kantō Plain. The rest consists of the hills and mountains that form the land borders. In official census count on October 1, 2010 by the Japan Statistics Bureau, the population was 42,607,376 amounting to approximately one third of the total population of Japan.