"Oni", which can be translated as "Devil" or "Demon" (name in which the film is known in English) is the story of two brothers who live in the mountains with their old mother. The brothers are hunters, and their mother is very ill and frail due to her age. One night the two hunters decide to go deep into the woods in order to hunt deer. The brothers set traps for their prey, which they intend to kill with their arrows. While the younger of the brothers is setting up a trap near a tree, a pale white hand comes from above and grabs him from the hair, pulling him into the crop the tree. In panic, the captured hunter calls for help, and his older brother arrives with his bow and arrow ready to shoot. The shoot is difficult, but the hunter manages to save his brother, as the arrow severed the arm that was holding him. The two brothers check the amputated arm and discover it's a demon's arm. They decide to return home and take the arm with them. When they finally get home, the two hunters will make a shocking discovery, when they find that their mother is hurt, and her arm amputated.
As in most of his early shorts, the story of "Oni" was written by director Kihachiro Kawamoto himself, taking inspiration from ancient Japanese folklore. In "Oni", Kawamoto presents a fable which explores two main concepts: the fear and respect to the spirits of the woods, and most importantly, the fear of old age. In Kawamoto's "Oni", when age becomes too much for old people, they become demons willing to eat their own children. The demon in "Oni", originally a frail woman weakened by her old age, becomes a monster in order to devour her sons. However, while Kawamoto could make his story a full fledged horror tale, he actually makes of "Oni" a tragedy. After the horror has been overcame, what is left is an ominous sense of sadness. The woman's transformation is not only a horror, but a tragedy. It's not treated as something she willingly wants, but something that actually possesses her and dehumanizes her. This dehumanization of old people with age may be a commentary on the mental degeneration that old age can bring.
In "Oni", Kawamoto displays his craft at his best, showing not only his roots at Bunraku theatre, but also the great influence that Noh theatre had in his formative years. "Oni" works like a Noh play, though certainly, Kawamoto's film is anything but stagy. The camera-work is highly dynamic, and by creatively playing with light and shadows (work of cinematography by Minoru Tamura and Ken Yoshioka), Kawamoto gives his story a surreal atmosphere that suits perfectly the story's narrative style, which works like an ancient fable. In "Oni", Kawamoto creates one of his most impressive puppets in the Oni herself, which is based on the Japanese artistic representations of the demons. The stylish demonic face looks impressive when captured by the camera of Tamura and Yoshioka. The film is silent, and the story is narrated in intertitles. However, this aren't intertitles as those of classic silent cinema, but dynamic texts that move and fade following the film's visual design, flowing with its rhythm, being themselves an integral part of the film.
Visually breathtaking, and full of a haunting beauty, Kihachiro Kawamoto's "Oni" is a powerful fable that displays perfectly the craftsmanship of the legendary puppet maker. With its surreal cinematography and its brilliant music (a score in the traditional way by Seiji Tsuruzawa), "Oni" is almost like watching the traditional Japanese art forms come alive through the magic of cinema. Melancholic and ethereal, "Oni" is more than a supernatural horror film, it's a powerful drama that in barely 8 minutes presents the tragedy of losing oneself in old age. After "Oni", Kawamoto would continue working in several short films of the same style, in which he would tackle classic themes of Japanese folklore, creating several masterpiece of stop-motion animation in the process.