Marquess was a Japanese diplomat and businessman.
He was born in Suà  Province, a son of Mitsuto Inoue. Katsunosuke was adopted by his uncle, Kaoru Inoue, after his father died in 1869.
Inoue served as Minister Plenipotentiary to Belgium in 1898. In 1898-1906, he served as Minister Plenipotentiary in Berlin.
He was Japan's ambassador in Germany (1906-1908), in Chile (1910âÂÂ1913) and in the United Kingdom in 1913-1916.
Inoue was a director of the Manchurian Railway.