The year is Genroku, during the reign of Tokugawa Tsunayoshi. In a remote, snowbound village deep in the mountains, a body is discovered. The scene is gruesome—flesh from chest to abdomen has been savagely torn apart, as if by a relentless saw. Someone mutters: "The Saw Demon... It must be the Saw Demon’s doing..." As the cold rain continues to fall, sealing the village from the outside world, hidden motives and quiet fears begin to intertwine.