The total area 17,000 km2 covers more than half of the Region extending over Tokyo , Saitama Prefecture , Kanagawa Prefecture , Chiba Prefecture , Gunma Prefecture , and Tochigi Prefecture .
The total area 17,000 km2 covers more than half of the region . It extends over Tokyo , Saitama Prefecture , Kanagawa Prefecture , Chiba Prefecture , Gunma Prefecture , and Tochigi Prefecture .