The are a group of five Japanese swords. Three are , one an Imperial Property, and one a holy relic of Nichiren Buddhism. Among the five, some regard Dà Âjigiri as "the yokozuna of all Japanese swords" along with à Âkanehira ().
As of 2017, the term is widely-recognized among Japanese sword connoisseurs. For example, the national institute uses the word in an explanation for Mikazuki. Although some researchers claim the term dates back to the Muromachi period (1333âÂÂ1573), its origin is unknown. Suiken Fukunaga cites a book written in the fifth year of Genroku (1692âÂÂ1693), so the term is traceable back to at least the late 17th century if the citation is to be believed.
Kanzan Sato commented, in terms of pure quality from the viewpoint of modern sword connoisseurs, although they are undoubtedly five of the greatest swords, it is doubtful whether they are the five greatest swords. He guessed the criteria of this selection include the values of legends associated to these famous swords.
Sometimes the selection differs from the following list. For instance, a list by Kanzan Sato includes , an Imperial Property of Japan, instead of Onimaru (although in other parts of the same book Sato contradicts himself and uses the same list as the following ).
All five swords in this list are included in the Kyà Âhà  Meibutsuchà Â, a sword catalogue commissioned by Tokugawa Yoshimune, the eighth shogun of the Tokugawa shogunate, and compiled by the Hon'ami clan, who were renowned authorities in sword appraisal. Swords listed in the Kyà Âhà  Meibutsuchà  are traditionally given the honorary title , which is prefixed to their names. Named Japanese swords are typically referred to in combination with the name of their swordsmith. For example, the Dà Âjigiri, one of the Tenka-Goken included in the catalogue, is referred to as .