[1] In 1865 he studied abroad in London with 15 other students from Satsuma, including Mori Arinori, Nagasawa Kanaye, Yoshida Kiyonari, and Godai Tomoatsu.

He went to the United States with 5 other Satsuma students to live at a vineyard in Brocton, New York, with Thomas Lake Harris, but returned to Japan with Mori in 1868.

[2] He became the first resident minister from Japan in Europe in 1870, assisted by Shioda Saburo [ja] and Frederic Marshall, an English lawyer and journalist.

Harry Parkes objected to his appointment because of his inexperience and the size of his portfolio, which was made up of Britain, France, and Prussia.

Sameshima's credentials as a charge d'affairs was not initially accepted in the United Kingdom, though it was in Prussia and France.