Rikishi (力士) is the Japanese term for a professional sumo wrestler. The two kanji characters that make up the word are "strength/power" and "gentleman/samurai"; consequently, and more idiomatically, 'a gentleman of strength'. This is reflective of the strength and toughness expected of a sumo wrestler and the gentleman samurai image still afforded to sumo wrestlers who have continued into modern times to dress as the samurai of old.

In popular use, the term rikishi can mean any sumo wrestler and an alternative term to sumotori (sumo practitioner) or the more colloquial sumosan. Within the world of sumo, rikishi is used as a catch-all term for wrestlers who're in the lower, un-salaried divisions of jonokuchi, jonidan, sandanme, and makushita. The more prestigious term sekitori is used to refer to wrestlers who have risen to the two highest divisions of jūryō and makuuchi and who have significantly more status, privilege and salary than their lower-division counterparts, as enumerated here. For details about the differences in competition between divisions see Professional sumo divisions.

Lifestyle of rikishi

The life of a sumo wrestler is strictly regimented, and has detailed prescriptions and rules for rikishi that have been observed for centuries, so much so that rikishi can be seen more as a way of life than a career.

They are expected to grow their hair long to form a topknot, or chonmage, similar to the samurai hairstyles of the Edo Period. Furthermore, they're expected to wear the chonmage and traditional Japanese dress at all times when in public. Sumo life centres around the training stables to which all active wrestlers belong. In addition, most wrestlers, and all junior ones, live in their stable in a dormitory style: training, cleaning, eating, sleeping and socialising together. For more details, see Life as a professional sumo wrestler.

Foreign-born rikishi

Professional sumo is practised exclusively in Japan, but wrestlers of additional nationalities participate. As of August 2009 there were 55 wrestlers officially listed as foreigners. In July 2007, there were 19 foreigners in the top two divisions, which was an all-time record, and for the first time a majority of wrestlers in the top san'yaku ranks were from overseas. More recently, the ratio of foreigners has stabilised and as of November 2011 there were 18 foreigners in the two top divisions.

A Japanese-American, Toyonishiki, and the Korean-born Rikidōzan achieved sekitori status prior to World War II, but neither were officially listed as foreigners. The first non-Asian to achieve fame and fortune in sumo was Hawaii-born Takamiyama. He reached the top division in 1968 and in 1972 became the first foreigner to win the top division championship. He was followed by a fellow Hawaii-born 660 pound mega-weight, Konishiki of ethnic Samoan descent, the first foreigner to reach the rank of ōzeki in 1987; and the native Hawaiian Akebono, who became the first foreign-born yokozuna in 1993. Musashimaru, born in Samoa but from Hawaii, became the second foreigner to reach sumo's top rank in 1999. The four most recent yokozuna, retired Asashōryū, and still active Hakuhō, Harumafuji Kōhei and Kakuryū Rikisaburō are all Mongolian. In 2012, the Mongolian Kyokutenhō became the oldest wrestler in modern history to win a top division championship. Wrestlers from Eastern European countries such as Georgia and Russia have additionally found success in the upper levels of sumo. In 2005 Kotoōshū from Bulgaria became the first wrestler of European birth to attain the ōzeki ranking and the first to win a top division championship. In another milestone, Brazilian Ryūkō Gō became the first foreign born wrestler to be given makushita tsukedashi status.

Until relatively recently, the Japan Sumo Association had no restrictions at all on the number of foreigners allowed in professional sumo. In May 1992, shortly after the Ōshima stable had recruited six Mongolians at the same time, the Sumo Association's new director Dewanoumi, the former yokozuna Sadanoyama, announced that he was considering limiting the number of overseas recruits per stable and in sumo overall. There was no official ruling, but no stable recruited any foreigners for the next six years. This unofficial ban was then relaxed, but only two new foreigners per stable were allowed, until the total number reached 40. Then in 2002, a one foreigner per stable policy was officially adopted, though the ban wasn't retroactive, so foreigners recruited before the changes were unaffected. Though the move has been met with criticism, there are no plans to relax the restrictions at this time. Originally, it was possible for a place in a stable to open up if a foreign born wrestler acquired Japanese citizenship. This occurred when Hisanoumi changed his nationality from Tongan at the end of 2006, allowing another Tongan to enter his stable, and Kyokutenhō's change of citizenship allowed Ōshima stable to recruit Mongolian Kyokushūhō in May 2007. Notwithstanding on February 23, 2010 the Sumo Association announced that it had changed its definition of "foreign" to "foreign-born" (gaikoku shusshin), meaning that even naturalised Japanese citizens will be considered as foreigners if they were born outside Japan. The restriction on one foreign wrestler per stable was additionally reconfirmed. As Japanese law doesn't recognise subcategories of Japanese citizen, this unique treatment of naturalised citizens might well be illegal under Japanese law, although the restriction has never been challenged in court.

Rikishi in contrast to additional martial arts practitioners

While sumo is considered a martial art, it diverges from the typical Eastern style both at the surface and at its heart. Whereas most martial arts award promotions to practitioners through time and practice, a rikishi's sumo rank can be gained and lost every two months in the official tournaments. Conversely, in more common Japanese martial arts (such as karate), ranks are gained after passing a single test, and practitioners of karate aren't normally demoted, even after repeated poor performances at tournaments. This divergence from additional martial arts creates a high-pressure, high-intensity environment for rikishi. All the benefits that sekitori wrestlers receive can be taken from them if they fail to maintain a high level of achievement in each official tournament (or honbasho).

Furthermore, sumo doesn't provide any means of achievement besides the official tournaments. A rikishi's rank is determined solely by his number of wins throughout an official tournament. On the additional hand, in a large number of additional Eastern martial arts, competitors can display their skill by performing standard routines, called kata or forms, to receive recognition. Thus, sumo wrestlers are quite specialised fighters who train to win their bouts using good technique, as this is their only means of gaining better privileges in their stables and higher salaries.

Former rikishi in mixed martial arts

The numerous differences between sumo and its martial arts counterparts haven't deterred a large number of former sumo wrestlers from competing in mixed martial arts. Most have had limited achievement; perhaps the most successful sumo wrestler to have competed in MMA is Tadao Yasuda who holds a record of two wins and four losses. Sumo wrestlers are seen as generally ineffective in MMA because the sports are vastly different from one another in achieving victory; striking techniques and submissions are required for MMA and neither are taught in sumo wrestling. A Sumo wrestler would need to train in MMA techniques which hasn't been the case in the past, as the few sumo wrestlers of distinction to compete in MMA did so for financial reasons and not a career change. A few key sumo techniques which require grabbing the belt or pants of the opponent additionally become ineffective, as this is illegal in MMA.

Other sumo wrestlers to have fought in mixed martial arts include Alan Karaev, Kōji Kitao, Henry Armstrong Miller, Akebono Tarō, Teila Tuli and Wakashoyo. Former UFC Light Heavyweight Champion Lyoto Machida additionally has a sumo background but his main style is Shotokan Karate.