@inproceedings{oai:kokubunken.repo.nii.ac.jp:00003971,
 author = {山口, 博 and YAMAGUCHI, Hiroshi},
 book = {国際日本文学研究集会会議録, PROCEEDINGS OF INTERNATIONAL CONFERENCE ON JAPANESE LITERATURE},
 issue = {10},
 month = {Mar},
 note = {pdf, In the long history of the establishment of the Manyôshû, which extends as far as the early Heian period, there is a text among those definitely ascertained to have been a source for compilation, (i.e. the so-called ur-manyôshû) in which appear headings such as "Hatsuseno Asakurano Amenoshita Shiroshimesu Sumera Mikotono Miyo."
This ur-manyôshû corresponds to poems 1 through 53 of the first book of the present Manyôshû, beginning with the poem of the Yûryaku Emperor and ending with those of the time of move to the Fujiwaranomiya capital (A.D. 694, Shuchô 8) in the jitô reign. The text of this ur-manyôshû is thought to date from the Keiun era (704-707) of the reign of the Monmu Emperor.
The foreign relations of the Japanese court had been forced into a defensive posture with the defeat in Korean diplomacy in the 7th century, and during the half century of the reigns of Tenmu and jitô, no envoys were sent to the Tang Court; instead, the court was preoccupied with consolidating the domestic polity. In the first year of the Taihô era (701), the format for diplomatic documents (Shôshoshiki `rescript style') was first defined under the ritsuryô system, and the next year saw a shift towards a more aggressive foreign policy with the dispatch of an envoy to China. Both the Nihonshoki and the Fudoki, reflect in their accentuation of foreign relations, this change in the political situation. And the same would appear to be the case with the ur-manyôshû, as well.
What does the expression 'Amenoshita Shirosimesu Sumera Mikoto'signify? The corresponding heading in the Nihonshoki reads "ohatuseno Wakatakeno Sumera Mikoto," while that in the Kojiki reads "Oohatuse Wakatakeno Mikoto Hatuseno Asakuranomiyani mashimashite Amenoshita shirashimeshiki." The ur-manyôshû's weighty expression "Amenoshita Shirashimesu" comes from the language of diplomatic documents in the shôshoshiki, the bulk of examples appearing in imperial edicts and memorials to the throne.
Why does this usage first appear with the Yûryaku Emperor? In the written history of relations between China and Japan, Himiko lies hidden beyond the horizon, whereas Waô-Bu is accorded the role of the heroic king. The great king who suppressed the Kudara and contested the authority of Kôkuri and Nansen is Waô-Bu, i.e.Yûryaku. Why is his poem directly followed by one of the Jomei Emperor? It was Jomei who initiated (in 630) the embassies to Tang which formed the basis of Japan's foreign policy in that age.
Detailed accounts of the envoys between China and Japan appear in contemporary Chinese historical records, as well.
Like the opening poem of the Chinese classic Book of Poetry, Yûryaku's poem which begins the ur-manyôshû is a love poem transformed to sing of a heroic king's control over the land. Jomei's poem, in turn, is concerned precisely with administration of the state domain. Indeed, we can say that the compilation of the ur-manyôshû was a literary enterprise in praise of the ritsuryô state and its system of fiefs, conscious of the proximity of the Tang empire and of Japan's international situation in East Asia. In the second year of Taihô(702), Awata no Mahito, who had played a role in drawing up the Rituryô code, was sent as an envoy to China, and his Party included Yamanoue-no-Okura. The ur-manyôshû was compiled shortly after their return from China.},
 pages = {15--23},
 publisher = {国文学研究資料館},
 title = {研究発表　8世紀東アジア政治状況の中における万葉集の成立},
 year = {1987},
 yomi = {ヤマグチ, ヒロシ}
}