Detective Mamoru Akasaka is used to catching criminals and solving fast-paced cases in Tokyo, but he has never imagined that his job would send him to the quiet village of Hinamizawa. Disguised as a tourist, Akasaka decides to take in the sights, all while gathering information for his true mission: to find a kidnapped child.

The dam construction project in Hinamizawa threatens to decimate the village, and a group of villagers has kidnapped the grandson of the Minister of Construction, holding him ransom in exchange for the project's cancellation. Akasaka must find the boy before things get too out of hand, all while trying to keep his cover. Taking place a few years before the main storyline of Higurashi, Himatsubushi-hen follows Akasaka as he navigates a village where enemies abound. However, he finds a friend in a young girl named Rika Furude, who knows far more than she should about their present situation, and about what might happen next...