A very important piece of information that also needs to be added to these reviews, is that this story is completely true.
It happened in 1936, at a time when such actions becoming public would normally shock any society. Abe however was treated with mercy (given her fragile mental state), and after the initial shock died down, she became quite a female hero in her country.
I'm frankly appalled by some reviews I've read in other places that compare this to legal porn and nothing more, as they are totally missing the point of it!
Even if you had never seen any other film in your life, you could see the technical and emotional effort that goes into making a film like this compared to "cheap porn".
In fact, the two lead actors were quite negatively affected emotionally and physically, (yes, they really did begin to waste away like that, they were mentally damaged by the experience, which proves the devotion they had to portraying their characters well).
You cannot tell a true story without showing events that really happened, so the sex scenes you see, (which were not faked by the way...well, apart from the asphyxiation obviously) were necessary to show the depth of the obsession that had formed between the couple. Unlike films like 9 Songs, which include such things, and then shout about the "realness" of the pointless sex scenes, just to get attention for their otherwise cowardly, artless film.
Ai No Corrida (In The Realm Of The Senses...how it's known in Japan, and how you may find it written on the DVD case) is beautifully shot, the music is perfect and unobtrusive, the actors genuinely brave and the fact that the story is true makes the things you see even more touching.
Forget the typically Western reactions you will have read in newspapers and magazines when this was at last released after 32 years in 2001, and open your mind to a touching true story.