"Manyoshu" (Japan's oldest anthology of poems) doesn't' contain the poems created by people from Kyushu, Sanin Sanyo, Shikoku because they wanted to keep the fact of the seizure of power a secret.
『萬葉集』に、九州・山陰山陽・四国の人の歌が無いのは、皇権簒奪の事実を隠すためである。