A former amateur sumo champion while at Nihon University, from 1975 to 1977 he was a sumo wrestler with the Hanakago stable and used the fighting name of Ōnoumi.
He then signed with K-1, a kickboxing and mixed martial arts organization, fighting under his old shikona (He uses the Latin script, appearing as "WAKASHOYO" rather than using the Japanese characters. The Sumo Association requested that Konishiki do the same thing in his post-sumo career).