Four posts which supported the corners (the east, west, south, and north corners; more precisely, the east-north, east-south, west-south, and west-north corners) of the roof were omitted when a tournament was held with the Emperor in attendance in April 1931.
屋根の四隅（東西南北、正しくは東北、東南、西南、西北）の柱を1931年（昭和6年）4月の天覧相撲のときに廃した。