In 1978, the village of Hinamizawa fiercely protests the government's plan to build a dam and destroy their home. When the Minister of Construction's son is kidnapped, the policeman Mamoru Akasaka visits Hinamizawa undercover to investigate the villagers' supposed involvement. He soon meets a young girl Rika Furude, who gives Akasaka an eerie warning: "Go back to Tokyo."
