Shiranui Dakuemon (Japanese: 不知火 諾右衛門; October 1801 – August 20, 1854, name also read as Shiranui Nagiemon) was a Japanese sumo wrestler from Uto, Higo Province. He was the sport's 8th yokozuna, and is the only yokozuna in history to have been demoted.
Source: “Shiranui Dakuemon”, English Wikipedia (CC BY-SA 4.0), excerpt