It is one of the five bankata posts in the Edo shogunate (namely, shoinban (castle guards), koshogumi (page corps), oban (hatamoto castle guards), kojunin (escort guards) and shinban (new guards)) and joined the troop formation when the shogun ventured out of the Edo Castle, to serve as security guards as well as to inspect weapons.
江戸幕府にあっては五番方（書院番・小姓組・大番・小十人・新番）のひとつで、特に将軍の江戸城外出時に隊列に加わり、警護に当たったほか、武器の検分役などの役目もあった。