Poems by Manyo poets such as Hitomaro were not included until "Gosen Wakashu" (Later Selected Collection of Japanese Poetry), but in the period of "Shuishu" (Collection of Gleanings of Japanese Poems) the number of poems suddenly increased, and this is considered relevant.
『後撰和歌集』まではあまり採られることのなかった人麻呂ら万葉歌人の作が、『拾遺集』になって急増するので、関連が考えられている。