Kayo first appeared as a literary category in the early twentieth century and was used to describe the songs of the Kojiki and the Nihon shoki to emphasize the view that they were oral songs dating from a period prior to the use of Chinese writing. The common poetic theme in both the Kojiki and the Nihon shoki is that of the ruler's marriage, which accounts for half of the songs in the Kojiki and one-third of the songs in the Nihon shoki. The Kojiki in fact has no songs at all after the sixth century and 88 songs out of its total of 112 appear in only six reigns, those of Jinmu, Yamato Takeru's father Keiko, Ojin, Nintoku, Ingyo, and Yuryaku. The Kojiki and the Nihon shoki are mytho-historical narratives of the formation of the imperial realm of Yamato, told from an impersonal perspective that is located outside the world of the text.

Manyoshu is Japan's oldest extant anthology of vernacular verse and the most revered repository of its classical poetic tradition. Just as Kojiki and Nihon shoki were compiled with the aid of earlier histories that do not survive, Manyoshu drew material from numerous other lost Japanese anthologies that are cited in its pages. The anthology was compiled during the greatest period of social change in premodern Japanese history. Manyoshu begins with a courting verse for a maiden gathering herbs on a hillside; it was purported to have been composed by Emperor Yuryaku, who was remembered as an exemplar. From the accession in 629 of the ruler known as Emperor Jomei, attributions of authorship gain historical plausibility; the number of poems markedly increases. Jomei ascended the throne after the death of the female sovereign Suiko, the last ruler represented in the Kojiki. The characterization of Manyoshu as a text that was widely read through the centuries is a modern myth.

The earliest extant works of the Japanese tradition date to the early eighth century, during the first decade of the Nara capital. The Kojiki and Nihon shoki are important for their content, a mix of myth, legend, and history, interspersed with poetry, and for the very different styles in which they were written. Kojiki is divided into three books, the first of which describes an early age of the gods, beginning with heaven and earth coming into existence and ending with accounts of the descent of Ninigi. The second book portrays the origins of rule by legendary sovereigns, starting with Jinmu, and describes the expansion of their realm, following reign-by-reign until that of the fifteenth legendary ruler, Ojin. The third book continues from the sixteenth ruler, Nintoku, to Suiko, whose reign represented the beginning of a new era for eighth-century historians. The Nihon shoki provides historians with a fundamental chronology of events in early Japan, especially for the seventh century.