The Chikugo River (筑後川, Chikugo-gawa?) is called "Chikushijirō" as a nickname. This river flows through Kumamoto, Ōita, Fukuoka and Saga prefectures in Japan. It rises under the Mount Aso, is 143 km long and is the longest river of Kyūshū. It enters to the Ariake Bay.
Coordinates: 33°09′N 130°21′E / 33.15°N 130.35°E / 33.15; 130.35