Oshiumi no Okuni (忍海大国)
OSHIUMI no Okuni (year of birth and death unknown) was a person in the Asuka period in Japan.
Another reading of his name in the old Japanese syllabary characters is 'OSHIUMI no Ohokuni'
His kabane (the hereditary title given by the Imperial Court) was Miyatsuko. In 674, he reported that silver was yielded when he was in the position of Kokushi (a provincial governor) of Tsushima Province. His official rank was Shokinge (the twelfth of twenty-six official ranks of Taiho Code).
He was described only in the article of the Emperor Tenmu on March 7, 674 of "Nihonshoki" (Chronicles of Japan). On that day, Kokushi of Tsushima Province, OSHIUMI no Miyatsuko Okuni reported, "Our Province yielded silver for the first time in Japan and we will offer it to the Imperial Court". With this deed, he received the official rank of Shokinge. This was the first discovery of a silver mine not just in Tsushima but in the entire Japan. No other achievements of his are known.