Passage: The Tone River (利根川, Tone-gawa) is a river in the Kantō region of Japan. It is 322 kilometers (200 mi) in length (the second longest in Japan after the Shinano) and has a drainage area of 16,840 square kilometers (6,500 sq mi) (the largest in Japan). It is nicknamed Bandō Tarō (坂東太郎); Bandō is an obsolete alias of the Kantō Region, and Tarō is a popular given name for an oldest son. It is regarded as one of the "Three Greatest Rivers" of Japan, the others being the Yoshino in Shikoku and the Chikugo in Kyūshū.

Question: where is the Tone River located?
Kantō region of Japan