List of sumo stables
The following is an alphabetical list of "heya" or training stables in professional sumo. All belong to one of five groups, called "ichimon". These groups, led by the stable by which each group is named, are in order of size: Dewanoumi "ichimon", Nishonoseki "ichimon", Tokitsukaze "ichimon", Takasago "ichimon" and Isegahama "ichimon". Occasionally there have been independent stables, but the Japan Sumo Association agreed at a director's meeting in July 2018 that all sumo elders must belong to one of the five "ichimon". The founding dates listed below are for the current incarnation of each stable ; in most cases this is not the first stable to exist under a given name, however. The number of stables peaked at 54, with the opening of Onoe stable in August 2006. In order to limit the over-proliferation of stables, the Japan Sumo Association introduced new rules the following month that greatly raised the qualifications needed by former wrestlers wishing to branch out (namely, those ranked below "yokozuna" or "ōzeki" must have spent at least 60 tournaments in the top "makuuchi" division or 25 in the titled "san'yaku" ranks). Discounting the special circumstances of the temporary closure of Kise  stable from 2010 until 2012, there were no new stables established for more than six years, while eleven folded, bringing the number of active stables down to 43. This sequence was ended by the opening of former "yokozuna" Musashimaru's Musashigawa stable in April 2013. Since this time the opening and closing of stables has stabilized and the number of stables has remained in the mid 40s. Pronunciation note. Due to a Japanese speech phenomenon known as "rendaku", when the word for stable, "heya", comes second in a compound word, the "h" in heya changes to "b" to become "beya . A sumo stable is pronounced in Japanese as sumo-beya" and Arashio stable, as an example, is pronounced "Arashio-beya". Active stables. There are 43 stables as of February 2022.