Ryūko made his tournament debut in the January 1957 "basho". He reached the "juryō" division in March 1967, and "makuuchi" in March 1968. The following year, he defeated "yokozuna" Taihō, scoring the first of his two "kinboshi". He was a runner-up in three top division tournaments, in March 1969, November 1969 and September 1970. His 1970 rise to "sanyaku" was followed by a 1971 torn achilles tendon, as a result of which he missed three successive tournaments and was demoted from "makuuchi" all the way down to the third "makushita" division. He returned to sumo, and after winning championships in the "makushita" and "juryo" divisions he regained his position in "makuuchi" in 1973. He scored his second "kinboshi" (against Kitanoumi) in 1974. He even managed a return to "sanyaku" at "komusubi" in January 1975, the first time that any wrestler had done this after dropping to "makushita". However, on the first match of the May tournament in that year, he tore the other Achilles tendon, and retired from sumo. He once told an interviewer that he thought "rikishi" wrestled too much - "Ninety days a year, such a severe tension, it's too much for a human being."