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This article is about an event in Higurashi When They Cry.

The Hinamizawa Dam Project (雛見沢ダム計画 Hinamizawa Damu Keikaku) was a government plan to build a dam in Hinamizawa, which would've resulted in the village being flooded and the eviction of over 2000 people. The conflict between the villagers and the government would come to be known as the Dam War. Though the project was cancelled, its resolution resulted in the phenomenon known as Oyashiro-sama's curse being created.


Japan was facing issues with transportation infrastructure, electricity, and flood control, and there were many dam projects in other places to assist with that. In the 1970's,[1] the government began plans to build a dam in Hinamizawa due to it having the right conditions and terrain for such a thing. The project started small, as it originally was just a way to control erosion.[2] Soon the dam reached a massive area, and if it were built, it would've resulted in a massive area up to Yagouchi being flooded.[3]

The villagers began protesting against the government and formed the Onigafuchi Guardians. Protests against the government appeared as sabotage of construction equipment by putting sugar cubes inside engines[4] and later attacking construction personnel. The police were unable to properly arrest anyone since there were no witnesses; due to the villagers' strong sense of unity, they would make cover stories for each other.[5] However, there were some villagers that were paid by the government to move out of Hinamizawa, and these villagers formed a pro-dam faction led by Satoko Houjou's parents. The pro-dam faction was ostracized by the villagers, with the Houjou family treated especially badly.

Resolution and Aftermath

In 1978 the Minister of Construction's son was kidnapped for ransom, and it seemed as though the Three Families and the Sonozaki family were behind it. The police investigated and managed to rescue his son, however it was enough for the dam project to halt construction. The project would become cancelled indefinitely the following year in 1979 when the dam construction foreman was murdered. Several people ganged up on him after a drunken dispute and bludgeoned him to death, then dismembered his corpse and each hid a piece. Every perpetrator except the ringleader was soon arrested, the latter having disappeared along with one of the arms.

One day in 1980 the Houjou couple died while on vacation from falling off a cliff, and only the husband's body was found. The similarity with the previous year's incident where someone died and someone disappeared made villagers believe that Oyashiro-sama's curse was claiming those who were involved with the dam project. Although the threat of the dam was gone, the villagers still ostracized the Houjou family for their support, even after the couple had died. The curse struck again in 1981 when Rika Furude's parents were made victims, as though they were part of the Onigafuchi Guardians they had a neutral stance on the matter.

True Nature


This article or section contains untagged major spoilers for the original Higurashi When They Cry and possibly the console-exclusive arcs. Readers who have not completed the main story are advised not to proceed further.

The kidnapping incident was actually masterminded by the organization Tokyo. They financed the creation of the Irie Clinic so they could research the virus Hinamizawa Syndrome, which was endemic to Hinamizawa. The agitation in the villagers caused by the dam war was theorized to result in many villagers becoming terminal patients of the disease, and so they pulled strings behind the scenes to cancel the project. The kidnapping of the Minister's son was done by Tetsurou Okonogi, leader of the Mountain Dogs who masqueraded as an unrelated party. The various deaths and disappearances in later years were all carried out by the Mountain Dogs under the guise of a curse.


  1. The exact date for the dam project's beginning is unclear. Tomitake's line in Onikakushi Day 9-2 says it began seven to eight years ago, placing its start date as 1974-1975. Shion's line in Watanagashi Day 4 says the project began over ten years ago before she were born. If Shion were 14 then the project's conception date places it at 1969.
  2. Watanagashi Day 4
  3. Onikakushi Day 9-2
  4. Watanagashi Day 10-2
  5. Himatsubushi Day 1