Japan's oldest extant chronicles, the Kojiki and the Nihon shoki, describe the trek of Kamu-yamato-ihare-biko no Mikoto from south Kyushu to the Yamato plain accompanied by hand-chosen clan (uji) heads. He is referred to by later historians as the first emperor, posthumously called Jimmu. At every step he was opposed by well-entrenched people whose conquest often required ingenuity and guile. The degree of their decimation seems to have been determined by the degree of their physical abnormality. For the bulk of his adversaries, the killing of their chiefs was all that was needed to bring them into line. But in extreme cases, such as the Tsuchigumo (earth spiders) who were people too primitive even to have responsible chiefs, pockets had to be eliminated by a process that was not completed until at least the time of the ruler Keikō, sometime in the fourth century A.D. When the physical and social differences were too great, it seems that assimilation was inconceivable and neighborly relations impossible.

These stories may look at first like an unnecessarily candid admission of the presence of other peoples, as the Eight Island Country of Japan was implicitly created for the enjoyment of the descendants of the Sun Goddess (Amaterasu). But by stressing the existence of others, the chosen were sharply distinguished from the undeserving, and the Yamato people could legitimately place themselves at the top of a scaled social ladder. The right to rule was therefore not predicated on prior occupation or existing status but on the act of divine creation.