The Nihongi names this island as Ohoshima stating it to have been the sixth island of the Grand Land of Eightfold Isles to have been created.2
1. Yasumaro. O, translated by Gustav Heldt. (2014) “Kojiki. An Account of Ancient Matters”. New York: Columbia University Press.
2. Aston. W.G. (1896) “Nihongi Volume 1: Chronicles of Japan from the Earliest Times to AD697”. Tuttle Publishing.
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