Wakanosato, whose real name was Rokuro Hidaka, was a prominent figure in sumo wrestling, having achieved the rank of Ozeki after his promotion following the Kyushu tournament in 1982. His athletic prowess and technique in the sport earned him recognition, winning two championships during his career. Wakanosato was born in Tanegashima, Kagoshima Prefecture, and was affectionately nicknamed 'Black Panther of Nankai' due to his slender physique and agility on the sumo ring.

In addition to his impressive wrestling career, Wakanosato garnered public attention when he married popular singer Mizue Takada in 1985, making headlines and bringing more visibility to his persona. After retiring in 1987, he adopted the elder name Matsukane and later established his own stable in sumo, nurturing younger wrestlers, including former komusubi Matsuhōzan.

In his later years, Wakanosato changed his elder name to Nishonoseki and took on significant roles within the Japan Sumo Association, where he served as a director and chief of the judging department. His passing is a loss to the sumo community, highlighting his contributions both as a wrestler and as an elder in the sport.