I got this film because it's about BDSM and has Japanese girls in it (particularly Yuki Mamiya). I heard it was graphic, which it is, definitely beyond what western viewers would be okay with, which is another point that interested me.
I expected a flimsy story line but eventually I got into the story. It's basically about a 17 year old school girl who gets kidnapped one day by her neighbour who has a basement in his home where he rapes her repeatedly and how later in life she works in an S&M club since she seemingly has developed a taste for abuse.
The film does a lot of narration over the scenes to explain her character and how she deals with what happened to her.
You really do sympathize with Naoko, particularly when she is younger as it is something that happens in real life. In that way it can be comparable to the infamous rape scene in Irreversible. Thus you do get wrapped up into it.
It is done in a... not mediocre style but... well given the premise you would picture a story with a lot more moping and scenes showing how broken Naoko is in everyday life. Oscar bait. It isn't that at all if you get me.
I recommend the film if you are mature enough to not get offended by graphic and sadistic sex and can appreciate the monologue of a person struggle with their trauma. It isn't too brilliantly written but it is done well enough.