These are 2 of my versions of the Ashinazuchi mask. Ashinazuchi, most commonly translated as "foot stroking elder", was the husband of Tenazuchi, hand stroking elder, and the father of Kushinadahime.
The only dance he appears in is Yamata No Orochi, most often the grand finale to an Iwami kagura performance.
In the dance, Susano finds Ashinazuchi, Tenazuchi, and Kushinade, the last of their eight daughters, lamenting as they prepare to sacrifice her to the great 8-headed serpent Yamata no Orochi. In return for defeating the serpent, Susano gets Kushinada as his wife.
The Yamata no Orochi story is a myth, but probably based on a legend, and legends are based on historical events. I spent 3 days walking along the Hi River area up in Izumo visiting many of the sites and shrines connected to the legend. This village in the valley below was the home of Ashinazuchi and his family.
Kagura mask Index