In a remote village in the Tanba region, peasants tremble as a string of earth tremors is interpreted as the escape attempts of Arakatsuma (also known as Daimajin), a violent divine spirit said to be trapped within the nearby mountain. The locals live in a constant mix of fear and reverence, believing the god must be appeased to keep catastrophe at bay. During a rite at the village shrine meant to pacify Daimajin, Samanosuke [Ryūtarō Gomi] stages a brutal coup, slaughtering Hanabusa Tadakiyo [Ryūzō Shimada] and his wife, while their children flee for safety with the help of the fearless Kogenta [Jun Fujimaki]. The moment marks a turning point: the power structure of the village collapses, and Samanosuke’s men break up the sacred gathering, forbidding such rituals from ever happening again. Shinobu, the elderly priestess [Otome Tsukimiya], warns of a dire curse, but her counsel goes unheeded as fear and hunger push the villagers toward darker deeds.
Kogenta helps the two children, Kozasa Hanabusa and Take-bō, escape to his aunt Shinobu’s home, and she guides them up into forbidden territory toward a towering, half-buried stone idol of the mountain god. The idol sits beside an ancient temple — a sanctuary kept safe by Shinobu’s knowledge. As the years pass, the children grow into adults in a village that has become more troubled and divided. The son, Tadafumi Hanabusa [Yoshihiko Aoyama], reaches his eighteenth birthday amid mounting hardship, as Samanosuke’s brutal rule imposes slavery on the villagers and threatens any sign of rebellion. Retainers loyal to the Hanabusa line begin to trickle back, hinting at the possibility of resistance, even as the mountain itself seems to resist the tyrant’s will.
Kogenta returns to rally the old retainers but is captured in the process. A boy named Take-bō [Shizuhiro Izoguchi] manages to send word to Tadafumi and Kozasa [Miwa Takada] that their friend is in danger, setting in motion a plan that tests all loyalties. Tadafumi’s attempt to rescue his ally becomes a trap, and Shinobu tries once more to intervene with calm warnings, but her pleas fall on deaf ears. Samanosuke retaliates with a cruel act, killing Shinobu and ordering the idol’s demolition. With her dying breath, Shinobu curses the tyrant and warns that destroying the idol will unleash the reawakened wrath of Arakatsuma within it.
An expedition up the mountain to smash the idol accidentally encounters Kozasa and Take-bō, forcing them to lead the soldiers to the statue. The men hammer at the idol’s head with a colossal chisel, but their triumph is brief: blood begins to drip from the stone, the earth cracks open, and the men are swallowed by the advancing fissures. Kozasa pleads with the god and begs it to spare her brother and Kogenta while punishing the wicked Samanosuke. At the fortress, Tadafumi and Kogenta are strapped to enormous crosses, awaiting their fates. Kozasa offers her life and tries to throw herself over the nearby waterfall, but the rock and earth exposing the idol’s lower half crumble away, and the stone figure stirs to life. The colossal Daimajin Arakatsuma, awakened by her tears, strides into the clearing and moves toward Samanosuke’s stronghold.
Daimajin rescues both Tadafumi and Kogenta and proceeds to utterly destroy the fortress. It impales Samanosuke with the chisel on its forehead, then turns its fury on the enemies surrounding them. Take-bō pleads for mercy, but Kozasa steps in to shield him, tears streaming down her face. She begs Daimajin to end the carnage, and when her tears fall on its stone feet, the god’s anger begins to lift. The Daimajin’s spirit withdraws from the statue, restoring its calm appearance just before it collapses into a heap of rubble. The village is left to witness the cost of tyranny and the power of a long-sealed force finally answering the call of a desperate plea, with new hope dawning as the mountain’s god returns to its quiet slumber.
