During the annual Watanagashi festival, Keiichi Maebara is informed by Jirou Tomitake and a mysterious woman, Miyo Takano, about "Oyashiro's curse". A series of murders and disappearances has occurred on the night of the festival for the past four years and are all supposedly caused by the curse of Hinamizawa's guardian deity, Oyashiro. The next day, Keiichi is interrogated by a police detective, Kuraudo Oishi, and learns that Tomitake committed suicide by clawing out his own throat, while Takano has gone missing. He becomes Oishi's informant. Keiichi notices changes in Rena Ryuuguu and Mion Sonozaki's behavior and suspects them of hiding something from him. He too is accused of keeping secrets because of his ties to Oishi. Keiichi delves deeper into the history of the curse with Oishi, and learns that one of the victims was Satoshi Houjou, a boy who had apparently transferred out of school in Hinamizawa before Keiichi arrived. At that point, Keiichi realizes that Rena has been eavesdropping on him the whole time.