It is made with Cypress bark.
This bark is harvested from sacred shrine groves,
including the Tsukimigaoka-jinja on the Dainichi-goe section of the UNESCO World Heritage Kumano Kodo pilgrimage route.

It was amazing to watch the bark peeling process that takes place high above the ground.
These young men only use two ropes to climb the giant trees.
I was very fortunate to spend an afternoon in the mountains watching this ancient occupation.
Posted by Pitt(ピット)
And I'm very glad that you could watch the work of Japanese traditional craft.
They, craftmen will be back to Hongu and work again about two weeks in this January. I think they will feel happy to see your article and photo!!