Keiichi Maebara, a recent transfer student in the remote village of Hinamizawa, spends carefree afternoons playing games with classmates Rena Ryugu, Mion Sonozaki, Rika Furude, and Satoko Hojo. Then he learns that a string of murders and disappearances has struck the village every year during the Watanagashi Festival, each tied to the local deity Oyashiro-sama. The friends he thought he knew begin to act strangely, and Keiichi cannot tell whether the danger is outside or sitting right beside him.