After graduating from Nihon University where he was twice the amateur sumo champion in 1968 and 1969, he made his professional debut in January 1970 at the age of 22, joining Hanakago stable. He was given makushita tsukedashi status, meaning he could begin in the third highest makushita division. He was undefeated in his first 14 matches and reached the jūryō division after just two tournaments. He was promoted to the top makuuchi division in January 1971.
After finishing as runner-up in the November 1971 and January 1972 tournaments he was promoted to sekiwake and took his first top division yūshō or championship in May 1972. He was promoted to ōzeki shortly afterwards and after winning his second championship with a perfect 15–0 score in May 1973 he was promoted to yokozuna. He won his first championship as a yokozuna in September, and in November 1973 he became the first wrestler ever to withdraw from a tournament while still managing to win it. He had split the webbing between his fingers in his Day 12 win over Takanohana, and lost the next day with his hand bandaged. As his only challenger on Day 13 had a fourth loss, he was able to sit out the last two days and still win the championship with a 12–2–1 record.
Wajima won three championships in 1974 but then went into a slump, and did not take another title until March 1976. In the late 1970s he was somewhat overshadowed by fellow yokozuna Kitanoumi, five years his junior. While Wajima had had a good personal record against him, holding a 19–10 advantage up to the end of 1977, Kitanoumi began to win their later encounters and overtook him in terms of championships won. Wajima's final record against him was 23-21. He took his fourteenth and final championship in November 1980, and retired in March 1981.
At the time, he held the third highest number of top division yūshō in history, behind only Kitanoumi and Taihō.
Wajima was an unconventional wrestler in many ways, and was looked on as a contrast to the strong and silent Kitanoumi. He was the only man ever to go as far as yokozuna without adopting a traditional shikona, instead fighting under his own surname of Wajima throughout his entire career. He was the first and to date only former collegiate competitor to be promoted to yokozuna. He was nicknamed the "Sumo Genius" because of his college background. His other departures from sumo norms included having his hair permed before growing a topknot, staying in luxury hotels and driving a Lincoln Continental whilst on regional sumo tours (jungyō), and associating himself with outsiders such as the yakuza and going out on late-night drinking sessions.
He was a great friend and rival of Takanohana, whom he had known since his university days. The two were promoted to ōzeki simultaneously in November 1972.
Wajima's preferred grip on the mawashi was hidari yotsu (right hand outside, left hand inside), and he was famed for the power of his so-called "golden left arm" which he would use to down his opponents by shitatenage or inner-arm throw. His other favourite kimarite included yori-kiri (force out) and tsuri-dashi (lift out).
Retirement from sumo
Following his retirement Wajima took over as oyakata, or head coach, of Hanakago stable in 1981, having married the eldest daughter of the previous stablemaster (former maegashira Onoumi) who had reached the mandatory retirement age for elders of 65. However, his time there as oyakata was controversial. He lacked leadership qualities and most unusually did not even live in the stable, preferring to commute. Hanakago declined to the point when it did not have any top-division wrestlers left. In 1982 his wife attempted suicide and he was demoted from his position as a judge as a result. The marriage eventually ended in divorce. In 1985 he was pressured by fellow oyakata to resign from the Sumo Association after it emerged that he was heavily in debt due to the failure of his chankonabe restaurant and had put up his share in the Association as collateral on a loan, a practice strictly forbidden. The stable folded completely with all its wrestlers transferring to the affiliated Hanaregoma stable.