Joined in the north of Iga City by the Tsuge-gawa River flowing from Mt. Aburahi-dake (694 meters) in the Suzuka mountain range and the Hattori-gawa River from Mt. Kasatori (845 meters) in the Nunobiki Mountains, the Kizu-gawa River changes its course west.
鈴鹿山脈の油日岳（標高694m）からの柘植川と、布引山地の笠取山（標高845m）からの服部川を伊賀市北部で合わせ、西流に転じる。