In an unnamed forest in what feels like ancient Japan, a woman named Himiko Shima Iwashita serves as the shaman and prophetess of the Sun God within the ruling kingdom of the Sun God people. Nearby, two other tribes populate the land: the Land People, who honor the ground, water, and animals, and the Mountain People, a rough, mute wanderer group tied together by a rope. A lone traveler named Takehiko Masao Kusakari emerges from the far side of the mountain and steps into the forest, shifting the balance of power and belief.
Himiko spends her days at a loom, weaving cloth, and she quietly delights in the news of Takehiko’s arrival. The court hums with ritual and prophecy, and the Sun God’s visions are discussed by the king, Ohkimi Yoshi Katō himself, who contemplates whether Mimaki Chōichirō Kawarasaki might eventually ascend the throne. Nashime Rentaro Mikuni, Himiko’s devoted servant, believes that she will be the rightful successor, claiming it as a direct command from the Sun God. Yet Mimaki confides in his brother Ikume Kenzō Kawarasaki that Himiko could be losing her prophetic touch because of her growing love for Takehiko, and that the Land God and Mountain God are false deities who should be overthrown to force belief in the Sun God alone.
When night falls, Takehiko visits Himiko in her quarters and reveals a startling truth: he is her half-brother. Despite the taboo, Himiko yields to desire and they sleep together while Adahime Rie Yokoyama, one of the ritual assistants, watches from a distance. The following night, Himiko addresses the court and proclaims that the Sun God requires the people to recognize the Land God and the Mountain God as valid powers as well. King Ohkimi accuses her of having lost her prophetic powers, but the moment is interrupted when Nashime assassinates the king during a distraction in the hall. With Ohkimi dead, Himiko assumes the throne and decrees that anyone who did not accept the Sun God’s words must be buried alive in the mountains.
Takehiko resists the pull of an unorthodox, incestuous bond and tries to leave the kingdom, choosing his own path over power. Adahime follows him, confessing her love and urging him to sleep with her, which he does. Himiko is horrified by this betrayal and orders Takehiko’s arrest. He is captured and brought back to her, where she orders torture and banishment. The Mountain People carry him up the mountain, and Adahime reappears to reunite with him as the ordeal unfolds. Meanwhile, back in the Sun God Kingdom, Nashime consoles a distraught Himiko, who ultimately yields to him physically. In the tinderbox of palace politics, Mimaki and Ikume plot to strip Himiko of her power.
Nashime confines Himiko to her room, while Mimaki seizes the throne as the new king. In a twist of fate, Nashime informs Mimaki that a young girl named Toyo will take Himiko’s place as the shaman and prophet of the Sun God. War erupts as Mimaki declares hostilities against the Land and Mountain God People. Takehiko and Adahime attempt to flee the realm, but they are intercepted and killed by Mimaki’s soldiers; their bodies are presented to Himiko, who is left devastated by the loss. Nashime acknowledges that Himiko has slipped into madness born of love, and, in a grim act of mercy or desperation, frees the imprisoned Mountain God People, who torture and kill Himiko in the mountains. Overcome with guilt, Nashime calls out to her in the forest.
In the climactic struggle, Mimaki kills Ikume in a sword duel that tears through the ridge and reshapes the landscape of power. Toyo rises as the new prophetess, declaring that the Sun God still resides within Himiko and that the vast and powerful Wei will demand slaves and offerings for centuries to come, unsettling Mimaki and troubling Nashime. Time moves forward to reveal the long arc of a country defined by its ancient tombs and modern life.
Years pass, and Nashime walks alone in the forest, weighed by grief and guilt for Himiko’s fate. A helicopter appears overhead, shattering the far-off sense of isolation. The camera pans outward to reveal that the forest sits atop a kofun, an ancient keyhole-shaped burial mound, with a suburban neighborhood of offices, houses, factories, and a highway encircling it. The film closes with aerial shots of more ancient tumuli scattered across Japan—quiet reminders that the past and present are in constant, uneasy contact as the credits roll.
