利根川
The is a major river in the northern Kantō region of Japan. A tributary of the Tone River, it is in length and drains an area of . Its source is at Mount Sukai on the boundary of the city of Nikkō in Tochigi Prefecture and it empties into the Tone River at the boundary of the city of Koga in Ibaraki Prefecture and the city of Kazo in Saitama Prefecture. It is classed as a First-class river by the Japanese government.