Greater Tokyo includes land in the Kantō region and also the Izu Islands and Ogasawara Islands. Ten percent (10%) of the Japanese people live in Tokyo, and as many as twenty percent (20%) of the population live around it. As of 2007, the population was 12,790,000. Tokyo is in a part of Japan called the Kantō Plain. Two big rivers run through Tokyo. One is the Arakawa River which runs from the north to the south, and flows into Tokyo Bay. The other is the Tama River which runs from the west to the east. The Tama River is a border between Tokyo and its neighbor city, Kawasaki.