The horror here isn't jump scares or gore, it's the slow realization that the Kannagi women have been feeding on immortality for centuries, and you watch it sink in that Yuta's only escape might cost him everything. The 1991 animation catches something grotesque in their stillness, the way their smiles don't move right. By the time you understand what Mermaid Forest actually is, the show has already made you complicit in wanting what the family has.
Legend holds that eating mermaid flesh grants eternal life, and for Yuta, who is 500 years old, and his friend Mana, the legend proved true. Most who try it either die or become monsters. Yuta and Mana are pulled into the world of the Kannagi family, owners of Mermaid Forest, where only an old woman and a white-haired girl remain. Fifty-five years ago, Towa Kannagi received mermaid blood from her sister Sawa to cure a deadly illness. She still looks young, apart from her white hair and a beastly arm. Hoping to restore her body, she relies on transfusions from young corpses supplied by the local doctor, Shiina. When Shiina wrongly takes Mana for dead, she is brought in so Towa can use her blood, and Yuta must try to save her. A mermaid may also lie buried in the hills, one that could return Yuta to normal. The OVA blends drama, fantasy, horror and mystery.
