EDO PERIOD (18TH CENTURY), BURNED SEAL DEME YUSUI [YASUHISA, ONO DEME VII (D.1766)] AND INSCRIBED IN GOLD LACQUER KITA KADEN NO KATACHI O MOTTE UTSU NARI

The name Sankojo comes from Sankobo (d.1532), a Buddhist monk who first carved a mask of this type. It is used mainly for old-man roles.

For another example of a Sankojo mask, see Christie's New York, 29 September, 2004, lot 312.