In a small, dark village in Japan, a group of villagers lives under the yoke of a dense fog that appears every night, bringing with it unsettling whispers and mysterious disappearances. Takashi, a young farmer, leads a quiet life until his younger sister, Yuki, vanishes without a trace during one of these eerie nights. Desperate to find her, Takashi embarks on a quest that will lead him to uncover ancient secrets and forgotten legends haunting the community.
As he investigates, he encounters an elderly woman who tells him about a local deity that demands sacrifices, suggesting that the fog is the work of a vengeful spirit that feeds on the fear and despair of the villagers. As the horrific stories of others who have gone missing come to light, Takashi realizes he must confront his own demons and his family's dark past.
With the help of a group of friends who join him in his search, Takashi ventures deep into the forest, where the line between reality and superstition begins to blur. Facing supernatural challenges and heart-wrenching trials, he and his group learn that true bravery lies not only in confronting external monsters but also in confronting internal fears. In a climactic night, Takashi must make decisions that will change his life and his community forever. Will he be able to rescue Yuki and break the curse that plagues his home?