I have been a Japanese bondage fan for a number of years now (and was even lucky enough to travel there a couple of times on my then-employer's dime) So I figure to throw in my 2.2 yen worth.
First of all, I suppose it's worth mentioning that just like any other genre, different people have different tastes. If your tastes fall towards lots of explicit close-ups of genitalia or away from Asian women, then the Japanese stuff probably won't put electrodes on your fancy's nipples (so to speak).
Oh, and yes, there are some uncensored vids out there. Often these are amateur or semi-professional productions of uneven quality. They are often more expensive, harder to get and rarely have any well known actresses. Very few in my experience have any scenes of note for the readers of the GIMP forum. If BD/SM is what you're looking for, I'd recommend to refrain from buying uncensored JAV unless you're really sure what you're getting (ie good scene descriptions plus lots of clean screencaps). If, on the other hand, amateur Japanese porn sounds appealing to you, then go for it.
Attackers
The JAV maker most familiar to GIMP readers is probably the Attackers company, producers of the "Shark," "Jyubaku" and a few less well-known series'.
Shark
The "Shark" series focuses on rape with bondage sometimes thrown in. Most are solidly done with high production values like real (sometimes on location) sets, believable (but not too believable) acting from the women (who rarely break character during the rape) and many drop-dead gorgeous women (a number of A-level JAV actresses have done 'Shark' vids).
The structure of the video is pretty much by the book, a setup scene, three sex scenes and sometimes a short expository ending scene. The "plots," such as they are, are formulaic (the usual one is a young woman wrongs a man or group of men - you'll see the same handful of actors - who turn the tables on her), though I notice from cover pics that they seem to be branching out a bit Hardcore SM scenes are but nonexistent.
If rape-fantasy is your kink, and you don't mind the quirks of JAV, it's hard to go wrong with any of the "Shark" series (stick to numbers above 40 or so, as the earlier ones are more hit-or-miss). Bound-sex fans will have to pick and choose their gems whereas bondage purists and hardcore SMers will likely have to look elsewhere.
Jyubaku
The "Jyubaku" series is the "Shark" series' bondage focused cousin. Most of what I wrote above about the "Shark" vids can be repeated verbatim for "Jyubaku." High production value and stunning women abound (pun intended!), though most are B-level or unknown actresses. The bondage is of the exquisite Japanese rope-master type, which sometimes walks along the border between erotica and living art.
I admit to not seeing any of the more recent additions to the series (above #30 or so), so some of this may have changed in later videos. The plots are basic and largely forgettable (ie, woman's husband owes some bad guys money. She pays off the debt by becoming a bondage slave for the bad guys). The women are generally more like 'coerced' or 'reluctant' participants rather than 'forced.' The sex is limited to a blowjob and some digital and object insertion into the vagina.
SM doesn't go much beyond suspension, clothespins and/or hot wax. I believe there are a few public urination scenes, but no scat or golden showers that I can recall.
This series then, is clearly aimed more at the bondage fan than anything. If that's your kink, then there are some definite hall-of-fame candidate videos for you in this series. Hardcore SMers will likely find some interesting ideas and positions (but please do not try the complex ropework or suspension yourself without extensive training and safety measures) but not much else. Bound-sex fans may have to pick and choose - so you'll need to find a site with good screencaps.