The cult originated in Shugendō practices on Mount Atago in Kyoto, and Atago Gongen is worshiped as a protector against fire. There is a Shinto shrine on Mount Atago, Kameoka, to the northwest of Kyoto. Atago Jinja is the head of nine hundred Atago shrines throughout Japan.
The white wild boar 白猪 (shirai, shira-i) is a messenger of the fire deity.
Source: The Atago shrines of Japan
Comparing the symbolism of the pig for other cultures, see The pig – symbolism:
“The twelfth sign of the Chinese zodiac is the pig, the embodiment of integrity. The Suidae family, to which the pigs belong, includes the wild boar, which for the Greeks, Celts and Japanese symbolizes the positive characteristics of strength and ferocity.
For Hindus, Vishnu and Rudra boars were celestial.
The wild boar and pig
The wild boar, like the moon, is a solar symbol.
The wild boar is the personification of the sun, and is associated with masculinity in its extreme manifestations such as: aggression, courage, struggle, blood lust, intemperance, gluttony, immorality and debauchery.
The “white pig” was considered a lunar animal, associated with female and fertility.
The Druids associate the wild boar with incarnation of spiritual power…Hindus worshiped the wild boar, as a source of life and fertility.
For the Celts the symbol of the wild boar expressed positive values.
This animal was considered the embodiment of courage and altruism.
The Scandinavians believed that the wild boar had prodigious abilities, so they wore helmets emblazoned with the image of the wild boar, or the mask of the animal, so that the soldiers on the battlefield had their protection.
The warrior, wearing a special helmet or wild boar mask, was under the protection of the goddess Freya.
In the tomb of the deceased the wild boar flesh was placed, because it was believed that this would give him the strength on the way to the afterlife.
For the Greeks, the Hittites and the Norse mythology the motif of the transformation of man into the wild boar often prevails.
Ancient Germanic wild boars
For Nordic Gods Frejra and Freji, the wild boar was considered a sacred animal.
Frejra called the wild boar sunny Gullinburstine, which means “from the golden bristles.”
For Freji the wild boars, Hildisvini, were her beloved herd; so, this animal was considered a symbol of protection of the goddess, as well as for military affairs and love.
The warriors of Odin in Valhalla ate the wild boar Zehrimnira every day, and at night its bones grew back the meat again.”
See also Swine