This was not a great Oshima film. It is a straightforward story and only has brief moments that begin to approach “transcendent madness.” It is not long enough or weird enough to invite deep thought about anything besides the basic story, a disappointment in an art film. (Or I could consider it a success if I was hanging on every subtle beat of the unfolding story and performances, as with great novelistic films.) The movie seems to invite deeper contemplation when Seki bites Toyoji's hand and things get slightly weird, but it then seems to leave that aside and not explore pain/sex in the way Oshima has before (in In the Realm of the Senses (1976) and a little bit in The Pleasures of the Flesh (1965)). It then moves along to the conclusion in a fully engaging way, but it doesn't have a big emotional or intellectual payoff. It's a nicely done, slightly poetic end to the story.
Probably some digging into symbols, like Seki being blinded, may lead somewhere, but I'm not sure. It crossed my mind that possibly the film is a fantastical realization of what Oshima or the writer think is happening psychologically when two lovers cuckold a woman's husband. But there are too many stories where the lovers actually do kill the husband (and in real life) for it to bear fruit as a cinematic realization of subconscious underpinnings. If it was intended as a beautiful and extravagant fantasy of love, intense sexual love, or doomed lovers, it's too restrained to flower into something truly moving, and compared to In the Realm of the Senses, the intensity level is low. Another metaphor that could bear investigation is the well, which I also thought about as an external narrative depiction of internal confrontations—as if when you cheat you toss the lover down the well and are constantly trying to forget him, but then you have to keep tossing leaves down there to cover him up, and find yourself periodically drawn back to the well. Even as I say it, it sounds silly, so I'm skeptical that this was their intention. (The film's basic scenario—and not anything in the filming itself—has very similar elements to Poe's "The Tell-Tale Heart" and James M. Cain's The Postman Always Rings Twice.)
I wish I had seen In the Realm of the Senses more recently, but my memory is that it was a deeply engaging shock of a movie, where you were fully enveloped in the mad, explorative passion of the two lovers, which culminates in its disturbing climax. Even though my memory is vague, I think Empire of Passion suffers in comparison, especially since it treads on some similar subject matter—as if Oshima was in the Hollywood studio system, being forced to do a sequel. A quick perusal of his filmography on IMDB shows that he was stuck (if I may presume) in television for about six years before the breakout success of In the Realm of the Senses. Perhaps he was desperate to stay in the theatrical filmmaking game, regardless of how similar the narrative territory was. I believe the older, pre-Criterion DVD was titled In the Realm of Passion, and a look at the Japanese words show that this is probably the more accurate title. (I will have to investigate Oshima's TV period because he may have been there willingly, like Rossellini.)
I find myself favoring early Oshima (first five or seven years perhaps), having had a similar lukewarm response to Taboo (1999) when it came out. His earlier films seem more radical in content and form. As horror or fantasy featuring ghostly apparitions (at least of the Japanese variety), this film does not bear up well in comparison to Kaidan (1964, Kobayashi), for example.