Set in the seemingly peaceful village of Hinamizawa in June 1983, the story follows Keiichi Maebara, a newcomer who quickly befriends a lively group of classmates: Rena, Mion, Satoko, and Rika. But beneath the cheerful surface lies a dark legacy—each year during the village’s Watanagashi Festival, someone dies and another disappears, rumored to be the curse of the local deity, Oyashiro-sama.
As Keiichi begins to notice strange behavior and inconsistencies among his friends, paranoia sets in. The story then fractures into multiple arcs—each a time loop where events reset after tragedy strikes. These arcs explore different perspectives, outcomes, and truths, gradually revealing the existence of the Hinamizawa Syndrome, a neurological disease that causes hallucinations, paranoia, and violence.
The central mystery revolves around Rika Furude, the shrine maiden who is aware of the loops and desperately seeks a way to break the cycle. With the help of a mysterious entity named Hanyuu, Rika tries to uncover the true cause of the tragedies and confront the hidden puppet masters behind the village’s fate.