日本の大相撲の起源はいつ
Since 1958, six Grand Sumo tournaments (Japanese: "honbasho") have been held each year: three at the Sumo Hall (or Ryōgoku Kokugikan) in Ryōgoku, Tokyo (January, May, and September), and one each in Osaka (March), Nagoya (July), and Fukuoka (November). Each tournament begins on a Sunday and runs for 15 days, ending also on a Sunday. Each wrestler in the top two divisions ("sekitori") has one match per day, while the lower-ranked wrestlers compete in seven bouts, about one every two days.
1958