"Higurashi no Naku Koro ni Gaiden: Nekogoroshi-hen" is a single-episode OVA that serves as a side story to the main "Higurashi no Naku Koro ni" series. The narrative centers on Keiichi Maebara, a transfer student who has recently moved to the rural village of Hinamizawa. Keiichi becomes involved in a peculiar incident when he learns about a stray cat that has been causing disturbances in the village. The villagers, particularly the local children, believe the cat is cursed and brings misfortune. Keiichi, driven by curiosity and a desire to prove his bravery, decides to confront the cat himself.

As Keiichi investigates, he discovers that the cat has been frequenting an abandoned shrine, a place shrouded in local superstition. The shrine is associated with Oyashiro-sama, the village's deity, and is believed to be a site of supernatural occurrences. Keiichi's actions escalate when he decides to capture the cat, leading to a tense and eerie confrontation. The episode delves into themes of paranoia, folklore, and the psychological strain of living in a community bound by tradition and fear.

The main characters include Keiichi Maebara, whose impulsive nature drives the plot, and his friends Rena Ryuuguu, Mion Sonozaki, and Rika Furude, who provide context about the village's customs and beliefs. Their interactions highlight the close-knit yet insular nature of Hinamizawa, where rumors and superstitions hold significant sway over the villagers' behavior. The OVA maintains the atmospheric tension and mystery characteristic of the "Higurashi" series, blending elements of horror and psychological drama.

The story is self-contained but ties into the broader narrative of the "Higurashi" universe, offering additional insight into the village's eerie atmosphere and the psychological dynamics of its inhabitants. It serves as a supplementary piece that enriches the lore of Hinamizawa without directly advancing the main plotlines of the series.