I had to watch this movie in my class, and I had a hard time getting through it. This is primarily because I wasn't familiarized with the Buddhist concepts throughout the film until after viewing it, which hindered my ability to understand the film, thus also my enjoyment of it. The Tale of Genji is based on 13 chapters of the Japanese epic novel by the same name, a novel that happens to be the first novel ever written (some time around the Seventh Century). Because the story is so old, and the language is so different, the novel becomes something comparable to Shakespeare to contemporary audiences: difficult to understand and almost unrelatable to some. That is why it was modernized into this animated film, with the physical character of the prince modeled after a contemporary rock star and the language updated to contemporary Japanese language.
However, if you are not familiar at all with The Tale of Genji (which is taught in Japanese schools), then the basic story of this film can be difficult (and downright confusing) to get through. It's basically about a young prince who suffers from the Oedipus complex without really knowing the nature of his obsession. He wanders around the film, fornicating with his wife, stepmother, and even lusts after his early-adolescent cousin. The morally twisted, yet slow-to-develop plot, is thematically justified by its Buddhist undertones, which, if is gone unfamiliarized before viewing the movie, can only further one's confusion. A good way to quickly familiarize yourself with this tale beforehand is to read Enchi's classic novel, "Masks." Otherwise, this ends up being a slow, twisted, and confusing film that will make you check your watch throughout its length and surprise you when it finally ends. My rating 6/10 (but only out of ignorance).