File No.34

File No.34 is a scrapbook created by Miyo Takano made to illustrate a conspiracy among Hinamizawa's residents. According to the scrapbook, aliens crash landed in a UFO in the Onigafuchi swamp and brought with them a parasite that dispersed and spread into the local populace. A lone surviving alien used advanced technology to treat the symptoms the parasite caused which led the citizens of Onigafuchi to worship the alien as "Oyashiro-sama". Since he could not cure the villagers of the parasite, the alien instead opted to restrain the parasite and ordered the villagers to never leave the village (as leaving the village would cause symptoms to flare up) and never accept anyone new into the village (so no one else becomes infected). Villagers called the symptoms that occurred after leaving the village "Oyashiro-sama's curse". However, as generations went by, the parasite became weaker and the rules the alien set became irrelevant. After the village was renamed to "Hinamizawa", fewer and fewer residents fully believed in Oyashiro-sama and his curse. In an effort to revive the legend of Oyashiro-sama and bring back the fear once associated with Onigafuchi, a group of religious fanatics, comprised largely of senior members of the three families, began to research how to bring back the parasite's strength. Takano postulates that the yearly murders are a result of the group's experiments on strengthening the parasite. She claims that the end result of the group's research would be a massive act of bioterrorism meant to reintroduce the stronger parasite into Hinamizawa's populace.

Though not described in the scrapbook, Rena Ryuuguu determines that the group's fifth attempt, in 1983, succeeded in reviving the parasite as Jirou Tomitake showed evidence of dying from a "maggot disease" that was symptomatic of the parasite. It is speculated by occultists that the Great Hinamizawa Disaster is a botched bioterrorism attempt that resulted in the destruction of Hinamizawa.