Shikona

A shikona (四股名 or 醜名^?) is a sumo wrestler's ring name.

As with standard Japanese names, a shikona consists of the equivalent of a 'surname' and a 'given' name, and the full name is written surname first. However, the given name is rarely used outside formal or ceremonial occasions. Thus, the former yokozuna Asashōryū Akinori is usually referred to as simply Asashōryū. When addressing a sumo wrestler of the makuuchi or jūryō divisions, the suffix -zeki (関) should be used instead of the usual Japanese -san. The given name is often, but not always, the wrestler's actual name, though it generally resembles a Japanese male given name. These are changed more often than the surname of the shikona, at the whim of the individual wrestler. Foreign wrestlers always take a different given name, which is invariably a Japanese male given name.

Often, on first joining professional sumo, a wrestler's shikona is the same as his family name. As a wrestler rises through the ranks of sumo, there is an expectation that he will change his shikona to something different than his family name. Often stables expect their wrestler to adopt a new shikona upon entering the professional jūryō division. However, the timing depends on the naming traditions of individual stables. The wrestlers at Kokonoe stable for example, often adopt a different shikona upon entering the lower sandanme division, while wrestlers at Sadogatake stable generally take a shikona different from their family names from joining as a trainee, even if that shikona is simply the character 琴　(read: koto) attached to the beginning of their family names.

The naming choices for wrestlers vary widely depending on the individual stable's tradition and somewhat less on the preferences of the wrestler. For example, Oguruma stable has the tradition of its wrestlers eventually adopting a shikona ending in the character 風 (read:kaze), which derives from the name of the stable's founder, Kotokaze. In another example of a naming tradition, many but not all wrestlers from the long established Dewanoumi stable adopt a shikona beginning with the characters 出羽 (read:dewa), derived from the name of the stable. On an individual basis, many wrestlers' shikona are often associated with where they are from. One example is the prevalence of wrestler's from Hokkaidō who use the first character Hokkaidō, which is 北, meaning north, in their shikona.

...
Wikipedia