It has been interesting to hear other students' reactions to this film, since I suspect I would have felt similarly nonplussed about the film a few years ago. It's only because of the Intro to Japanese Lit class I'm taking (and about 10 years of watching classic Japanese cinema) that I feel like I fully "get" what this movie and other classic Japanese films are trying to accomplish.
Early Japanese ghost literature is heavily based on tradition and the repetition of themes and story structures. Rather than focusing on creating something entirely new, the authors of classic Japanese ghost stories were attempting to showcase their knowledge of earlier Japanese literature by quoting specific elements of stories that had been written before, many of which were based on even earlier Chinese folk literature. Learning the themes and patterns of these stories is a bit like learning a code that unlocks a deeper layer of meaning.
As is seen in _Kwaidan_, most of these stories have a similar style of pacing, which emulates that of Japanese Noh theater. The action is generally very slow at the beginning, and it gradually picks up as the story progresses. "Black Hair" achieves this nicely with its plodding initial storyline followed by the closeups of the galloping horse's hooves as the samurai returns home and culminating in the frenetically crazy hair madness that occurs at the end.
The stories are also heavily location oriented. Any specific location mentioned is generally intended to draw a parallel between the author's story and some classic folklore that came before it. Many of these stories begin with a long journey through several regions that culminates in the protagonist's encounter with the supernatural. Ghostly encounters generally take place in nature, especially in the woods or mountains, and usually at night. The scene of the ghostly encounter is meant to seem like a timeless no-man's land.
Borders and gateways are a common theme, and the lines between real and supernatural realms tend to become blurred. It is often hard to tell the difference between the living and dead or to tell a dream from reality.
Ghosts are usually women who somehow manage to trick a mortal man. Some scholars have suggested that this theme was meant to warn men at the time against becoming party to the breakdown of traditional Japanese patriarchal society.
Themes from Japanese ghost stories pop up even in Japanese films outside of the horror genre and are often used to heighten the tension and suspense in a way that viewers unfamiliar with J-lit and films would not necessarily catch onto. For example, knowing the the tale of "The Woman in the Snow" makes the snow storm scene in Kurosawa's _Dersu Uzala_ even more suspenseful even though there is no supernatural element at work in the film. http://www.youtube.com/watch?v=IWaptYeM5Lg In _Musashi Miyamoto_, the first film in Hiroshi Inagaki's "Samurai Trilogy", an element of suspense is added when a samurai unexpectedly stumbles across a large house with a smoking chimney in the middle of a vast reed field, which is often the type of setting in which ghost story protagonists fall under a ghostly spell (as in Ueda Akinari's ghost story "The Reed-Choked House," which Mizoguchi's _Ugetsu_ was partially based on). Even though the "Samurai Trilogy" is a melodrama rather than a horror film, when the samurai finds two lone women cooking dinner inside the house, the viewer is made slightly uneasy by the too-idyllic setting as if the women might be ghosts about to trick him. In fact, the mortal women's actions in the film are very similar to those of the ghostly tricksters featured in Japanese horror stories.
On a side note, any Star Wars fans out there should watch Akira Kurosawa's 1958 film _The Hidden Fortress_. It's basically where George Lucas got much of the storyline for the first Star Wars movie. Imagine C-3PO and R2-D2 as bumbling samurais instead of robots. At about 3:30 into this clip, Lucas talks about his use of elements from _The Hidden Fortress_. http://www.youtube.com/watch?v=3eMvSjDZYb4&feature=related
He also provides some insight into Japanese cinema in general.
The East-West influence isn't a one-way street, either. The over-the-top color schemes used in _Kwaidan_ are extremely derivative of Douglas Sirk melodramas from the '50s. Compare "The Woman in the Snow" http://www.youtube.com/watch?v=Xg5wJQD2xHY to this clip from Sirk's _All That Heaven Allows_ http://www.youtube.com/watch?v=DBH97bWmAfM