The Jo masks are Old Man masks, which express the features of very old men, and there are many different types of such masks. The Mai-jo type, which includes Ishio-jo, Mai-jo and Shiwa-jo, is used for Jo-no-mai dances. The Ko-jo type, which includes Koushi-jo and Akobu-jo, is used when a god takes on the form of an old man. And the Morohige-jo type (the type with implanted mustache and beard), which includes Asakura-jo, Sanko-jo and Warai-jo, is used when a dead man takes on the form of an old man.

The Ishio-jo mask was named after the creator of this mask, Ishiobei Masatomo. Different from other jo masks, the Ishio-jo mask has deep-set eye holes with downcast eyes, which creates an imposing countenance. It has the done-up implanted hair, the implanted beard and drawn mustache. Totally, this mask has a highly stylized expression and even gives a nihilistic impression compared with the gentle Mai-jo mask. The Ishio-jo mask is used for an old man or the spirit of a plant or tree that performs an elegant, stately dance in such plays as “Yugyo Yanagi” and “Saigyo Zakura.”