A man from Tokyo, Gakuen Yamazawa, travels through a mountain village on his way back from a summer field trip, drawn by the legend of the village’s sole stream—the water that feeds from Demon Pond. The locals claim a dragon guards the pond and that the water is poison, a belief that threads through the villagers’ fear and ritual. In this secluded place, he meets Yuri Hagiwara, a woman who asks him to tell her a story. His second story unsettles her, and she refuses to let him stay, but her husband, Akira, welcomes Yamazawa as an old friend from Tokyo.
Akira has left the city to gather stories from the countryside, yet he now feels trapped by the very life he sought to escape. He has assumed the role of ringing the village bell at matins, vespers, and the night watches, a duty that binds him to the village and to a vow begun by a dying man named Yatabei. The vow holds that if the bell is not rung at the correct times, the water from Demon Pond will flood the Kotohiki Valley beneath Echizen’s Three Province Peak. In a twist of fate, Akira adopts the name Yatabei, marries Yuri, and resists the pull to return to Tokyo. Yamazawa, sensing a deeper truth behind the village’s rituals, decides to climb toward Demon Pond, and Akira joins him, leaving Yuri to bear the burden of the bell.
Ahead of them, magical forces stir. The giant crab Kanigoro and the carp Koishichi are dispatched from Demon Pond by Lady Myriad, the nurse of Dragon Pond’s Princess Shirayuki, to warn the villagers that rain will fail despite their offerings of broken pottery and the heads of cats and dogs. Koishichi recounts that the princess loves the prince of Serpent Pond, but if she flies to him, a flood will devastate the village; so she remains trapped at Demon Pond so long as the bell is rung at the right times.
A catfish priest named Black, who represents the prince of Serpent Pond, arrives bearing a letter from the prince for the princess. He fears the letter’s contents and his own imprisonment, worries that the message might instruct the princess to swallow him. The giant crab Kanigoro opens the small letter box, but inside there is only water.
Princess Shirayuki is driven by longing yet bound by an ancestral vow: she cannot leave as long as the bell must be rung at its appointed times, or the gods and buddhas will curse her and her kin, bringing ruin to both pond-dwellers and villagers. She rushes to destroy the bell, but at the last moment she hears Yuri singing a lullaby to her baby doll Taro, a sign of the human tenderness Yuri carries for Akira. The soothing song moves Shirayuki to reconsider her drastic act, and she chooses not to destroy the bell—understanding that the village’s fate is entwined with Yuri’s own sorrow.
That night, the village turns against Yuri, intending to sacrifice the most beautiful girl in the village to an ox in a ritual for rain. They bind her, but Akira frees her, explaining that Yamazawa had decided to return to his family, moved by Yuri’s lullaby. He urges the villagers to let Yuri go, but they resist. Yamazawa returns and denounces the village’s stubborn adherence to old traditions, revealing himself as a priest of the Honganji sect and a professor at Tokyo University. He argues that Japan remains shackled by the weight of bushidō and outdated customs.
The villagers demand Yuri, and a brutal confrontation ensues. Denkichi wields a long knife, while Akira fights with a scythe. Akira is wounded, and Hatsuo—an admirer of Yuri—seizes the scythe to continue the battle. Yuri, moved by the violence and the complex loyalties around her, seizes the weapon and takes her own life with it. Akira carries her away, fulfilling a promise to her that she would not be left behind, and begs Yamazawa to ring the bell one last time. Yamazawa agrees and ascends the bell tower as a dragon princess arrives, bringing a wave of destruction with her.
In that final reckoning, Akira reassures Yuri that her faith in the rightness of her feelings was correct, and he kills himself with the scythe. The dragon princess awakens Yuri to sing a final song with her doll before departing, a haunting mercy in the face of catastrophe. The closing image shifts to the village: Yamazawa stands as the new bellringer, with Hatsuo by Yuri’s home, holding her doll Taro, signaling a fragile, sorrowful continuity between duty, memory, and the human cost of keeping ancient promises.
