There is also another opinion about a prototype of this myth; Izumo Province was actually in a state of war with Koshi Province in those days, and "Izumo no kuni fudoki" (the topography of Izumo Province) states that 'eight mouths in Koshi' were suppressed in the tale of the place-name concerning Mori village, Ou county.
あるいはこの当時、出雲国は実際に越国（北陸地方）との交戦状態にあり、『出雲国風土記』には意宇（オウ）郡母里（モリ）郷（現在の島根県安来市）の地名説話において「越の八口」を平定したと記されており、これがこの神話の原型ではないかという説もある。