Yagyuu Binbokusai (柳生 敏木斎) is an elderly figure from the Gintama anime and manga. He is the grand patriarch of the Yagyuu Family and a sagely master of swordsmanship. Binbokusai was also mistakenly believed to be a "Butt Sand Sage" when some believed he could wipe his own butt with sandpaper without any pain due to having strengthened his posterior on the sands of a hot and brutal desert in an eastern land, however he was actually faking wiping his butt.