In Shuzo Shimada's *Kokoro no Furusato Mimasaka Densetsuko* (Thoughts on the Legends of Mimasaka, the Homeland of the Heart), there is a chapter titled "The Gongo of Nozoki-buchi," which records that the Gongo living in the deep pools of the Yoshii River dragged swimmers into the water[2]. Regarding its etymology, both Sosuke Uetsuki's *Tsuyama Kotoba* (Tsuyama Dialect) and Fumiaki Kishimoto's *Kyodo Hakkutsu Okayama Kotoba Gogen Tankenki* (Local Excavation: Okayama Dialect Etymology Expedition) convey two theories: that it is a corruption of the old name for kappa, "Kawako," and that it is connected to "Kongo," a deity that governs water[1].

The custom of calling kappa "Gongo" in Mimasaka is geographically contiguous with the dialect region of southern Okayama and the entire Chugoku region, where kappa are called "Kawako" (river child). It is believed that the "Kawako" lineage of dialect uniquely corrupted into "Gongo" in Tsuyama[1]. Today, rather than being feared as a terrifying apparition that warns against water accidents, it has transformed into a symbol of local heritage. Every summer in Tsuyama, the "Tsuyama Noryo Gongo Festival" is held on the banks of the Yoshii River. The "Gongo Bus" touring the city and the "Gongo-dori" shopping street have made it a beloved local specialty[3].