In the summer of 1983, Rena Ryuuguu and her friends are enjoying their days the way they always have: playing games and living a life of contentment in the village of Hinamizawa. But darkness is forming in Rena's heart, and even her closest friends may not be safe from it.

Rena's divorced father has recently found a new girlfriend, a sleazy woman named Rina Mamiya. Rena's hatred of her is solidified when she discovers that the woman and her true boyfriend are trying to swindle Rena's father out of his money. After a tumultuous confrontation with Rina about what she has learned, Rena realizes that she must resort to desperate measures to keep her father safe. When her friends notice that she is acting rather strange, they investigate what she has done, but instead of abandoning her as Rena assumed they would, they band together to support and help her.

However, when she discovers a shocking snag in her plans, Rena realizes that she may have trusted the wrong people, and begins to become highly suspicious of her friends and the other townspeople. And as she uncovers the truth about the town's long history of murders and disappearances, she realizes that only drastic actions can save the village from utter destruction.