日本武尊
In addition to archaeological findings indicating a local monarchy in Kibi Province as an important rival, the legend of the 4th-century Prince Yamato Takeru alludes to the borders of the Yamato and battlegrounds in the region; a frontier was near the later Izumo Province (eastern present-day Shimane Prefecture). Another frontier, in Kyūshū, was apparently north of present-day Kumamoto Prefecture. According to the legend, there was an eastern land in Honshū "whose people disobeyed the imperial court" and against whom Yamato Takeru was sent to fight. It is unclear if the rival country was near the Yamato nucleus or further away. Kai Province is mentioned as a location where prince Yamato Takeru traveled on his military expedition.