Morimasa, Prince Nashimoto was a member of the Japanese Imperial Family and a field marshal in the Imperial Japanese Army. An uncle-in-law of Hirohito, an uncle of his consort, Empress Kōjun, and the father-in-law of Crown Prince Euimin of Korea, Prince Nashimoto was the only member of the Imperial Family arrested for war crimes during the Allied occupation of Japan following defeat in the Second World War.

Rikugun-gensui , formal rank designations: Gensui-rikugun-taishō was the highest title in the pre-war Imperial Japanese military.