[1] The Ibo, Kako, Ichi, Yumesaki, and Chikusa rivers are collectively referred to as the Harima Gokawa, the five major rivers that flow into the Harima Sea.

The basin area is the second largest of the Harima Gokawa after the Kako River.

It runs through Tatsuno and divides Nakagawa to the west near Yobeku, Himeji, forming a delta.

On September 13, 1976, a landslide occurred in Fukuchi, Ichinomiya-cho due to the torrential rain of Typhoon Fran.

The spilled earth and sand filled the river channel and caused flooding.