In the summer of 1983, Keiichi Maebara moves from the city to the remote mountain village of Hinamizawa. He quickly befriends a close-knit group of girls at his new school: the cheerful Rena Ryuugu, the assertive Mion Sonozaki, the energetic Satoko Houjou, and the mysterious Rika Furude. Life in the quiet, rural village seems idyllic, and Keiichi settles in happily.

As the annual Watanagashi Festival approaches, a celebration dedicated to the village's patron deity Oyashiro, Keiichi learns of a dark history surrounding the event. Over the past four years, a string of murders and disappearances has occurred on the night of the festival, and the locals whisper that these are the result of a curse. Keiichi becomes drawn into the mystery after meeting a detective who is investigating these unsolved cases.

As he delves deeper, Keiichi's trust in his new friends begins to erode. Strange occurrences pile up: a sewing needle is found in his food, he is pursued by mysterious men, and he becomes convinced that Rena, Mion, and the others are hiding sinister secrets from him. Paranoia consumes him, and he can no longer trust his own eyes. The tension spirals into a horrifying and bloody climax.

However, the story does not end there. The narrative of the live-action television adaptation is structured across multiple arcs, each revisiting the same June 1983 timeframe from a different character's perspective. In this way, the true nature of the curse, the village's past, and the hidden motives of the residents are gradually revealed. The same initial events are seen through new lenses, and what seemed to be a straightforward curse gives way to a deeper and more complex conspiracy involving the village's powerful families and a secret experiment. The story explores the bonds of friendship, the destructive power of suspicion, and the lengths to which characters will go to protect the village or break free from its cycle of tragedy.