[1] Three are National Treasures of Japan, one an Imperial Property, and one a holy relic of Nichiren Buddhism.
Among the five, some regard Dōjigiri as "the yokozuna of all Japanese swords" along with Ōkanehira (ja:大包平).
[3] Although some researchers claim the term dates back to the Muromachi period (1333–1573),[2] its origin is unknown.
Suiken Fukunaga cites a book Yorozu Kaimono Chohōki (万買物調方記) written in the fifth year of Genroku (1692–1693),[4] so the term is traceable back to at least the late 17th century if the citation is to be believed.
[5] He guessed the criteria of this selection include the values of legends associated to these famous swords.