Haguroyama Masaji

was a Japanese professional sumo wrestler from Nakanokuchi, Niigata. He was the sport's 36th yokozuna. He was a yokozuna for a period of twelve years and three months dating from his promotion to that rank in May 1941 until his retirement in September 1953, After his retirement he was the head coach of Tatsunami stable until his death in 1969.

Career Haguroyama's birth name was . Haguroyama made his professional debut in January 1934 at age 19, joining Tatsunami stable. His progression was remarkably rapid. He passed through all the lower divisions in just one tournament each, After finishing as runner-up in the January 1941 tournament and winning his first top division title in May 1941 he was promoted to yokozuna. He chose the Shiranui style of yokozuna dohyō-iri (ring-entering ceremony) in honour of the recently deceased Tachiyama Mineemon. After three more runner-up performances he won his first championship as a yokozuna in May 1944.

Upon the retirement of his great rival Futabayama in November 1945 he became dominant, winning four consecutive tournaments. However, in November 1947 he severed his Achilles tendon and was out of action until May 1949. He won his final championship in January 1952 at age 37 with a perfect 15–0 record. It was his first tournament win in over four years. He retired in September 1953, when he was nearly 39.

He was known for his hard training and his great strength, and was said to be "made of steel."