As a young man, Mori was one of a number of students sent by Satsuma han secretly to England for study. After some time in the United States, he returned to Japan and entered into the Meiji government. He was sent to Washington DC in 1871 as Japan's first minister to the US, and while there oversaw a number of surveys of the American educational system.
He later served terms as ambassador to China, vice-minister of foreign affairs, and ambassador to England, among a number of other positions, before becoming Minister of Education in 1885. He held that position until his assassination in 1889.
- Marius Jansen, China in the Tokugawa World, Harvard University Press (1992), 114-115.