Surrounded by green mountain ranges, Yamanashi Prefecture is home to sites of ancient worship, most notably shrines dedicated to Mount Fuji. There is also a folk belief unique to Yamanashi, which many Japanese folklorists consider an enigma: Maruishi-gami, or “spherical stone gods.”

Names and natures do agree, as the Maruishi-gami is just what it’s called—a spherical stone. But are they natural or artificial? Hard to tell, it seems. How does one worship them? Depends on whom you ask. They appear to be a sort of dōso-jin, the roadside deity that offers protection to a traveler, but that’s not always the case.

Likely a remnant of primitive animism surviving into modern local culture, few locals are concerned about the origin of their stone gods, only paying them the respect that they deserve. As such, academic research is severely lacking on this subject and there remains a lot to be deciphered.

Though no survey has been done, it is estimated that there are over 700 Maruishi-gami across the prefecture, a majority of them found in Yamanashi City. The largest of its kind is located in the Nanoka-Ichiba neighborhood, a boulder seated on the throne of smaller rocks. Locally beloved, it remains in good care, placed upon a pedestal made of smaller Maruishi-gami.