"Nekohiki no Oruorane" is a supernatural mystery anime set in a secluded rural village where ancient traditions and folklore intertwine with the lives of its inhabitants. The narrative centers on a young man named Haruto, who returns to his ancestral home after the sudden disappearance of his older sister, Ayaka. Upon his arrival, Haruto discovers that the village is steeped in eerie customs, including a ritual known as the "Nekohiki," where villagers offer sacrifices to a mysterious entity believed to reside in the surrounding forests.

As Haruto delves deeper into the village's secrets, he encounters a enigmatic girl named Oruorane, who is shunned by the villagers and rumored to be connected to the Nekohiki ritual. Oruorane possesses an otherworldly aura and seems to know more about Ayaka's disappearance than she lets on. Haruto forms an uneasy alliance with her, driven by his determination to uncover the truth. Together, they navigate the village's labyrinthine traditions, uncovering dark truths about the sacrifices and the entity that demands them.

The plot unfolds through a series of flashbacks and revelations, gradually revealing the history of the Nekohiki ritual and its ties to Haruto's family. The village elders, who guard the ritual's secrets, become increasingly hostile as Haruto and Oruorane get closer to the truth. The story explores themes of guilt, sacrifice, and the weight of inherited legacies, as Haruto grapples with the moral implications of the ritual and his own role in the unfolding events.

Key characters include Haruto, whose determination and skepticism drive the investigation; Oruorane, whose mysterious past and connection to the ritual make her both an ally and a source of intrigue; and Ayaka, whose disappearance serves as the catalyst for the story. The village elders and other residents provide a backdrop of tension and superstition, their actions and beliefs shaping the narrative's progression. The anime balances its supernatural elements with a grounded exploration of human emotions and relationships, creating a compelling and atmospheric tale.