I'll preface this review with saying I watched the BLANC version of this film which, to my understanding, is the same as the NOIR version with the exception of the last 10-15 minutes or so. If that's the case, I think there wouldn't be much that would change my view since the bulk of the films are the same.

So, story wise: I did rate it quite highly in that simply because the story had a lot going for it. There's a lot of very interesting issues that we see through Yuki's experience and this is where the main issue of this movie comes from for me. The depth that the story explores with the prositution and host scene could've been so great to expand upon and explore the toll it takes on those within such an environment...instead, there is a strange (almost comic or blasé) tone over the whole film that makes these things seem either benign or comical in some areas. That alone makes watching the movie just....confusing. As a viewer, I just wasn't sure how I was supposed to be feeling. So much happens to Yuki, but there's almost no time in the movie to experience him feeling it, or for the viewer themselves, to emotionally register these events. There is some really shocking events that come up and the movie takes such a non-challant tone shift each time they happen that is so infuriating. As a result, the sexual experiences Yuki engages in are just non-events as far as the movie goes. There's no feeling that he's changing as a person because of it, or going through anything at all...skipping those scenes changes the film in no real way.
I'll say this though: I have no issue with sex scenes at all, in fact with a plot like this, I'd expect them. But, I'd expect them to play some role...to be meaningful in some way. Rather, besides one particular shocking event, they just weren't. Now, if we're doing sex scenes just for the fanservice or what have you: that's where the tone of the movie gets in the way again. The scenes themselves came across in such a boring way that even trying to enjoy them for what they were was impossible.

The whole concept of Aoyama also came across as really unecessary to me. Given the meaty-ness that the setting of host clubs and male prositution bars already gives the plot, I don't know why they needed to shift the story to this chemistry-less and quite forced feeling relationship arc. I almost feel the story would've been improved by removing Aoyama entirely and instead watching Yuki navigate this tragic downward spiral he finds himself on....or, if a singular romance interest was really needed, the other key male characters he interacts with (like Ryoma the host club owner and so on) could've played as more interesting characters to build tension off of.

As far as the acting goes: it was good, I suppose. The main leads were pretty forgettable and the only scenes I do remember came from actions done by the supporting cast - which, I'll say, I had more fun watching than the main leads. In saying that, no one was bad either. The chemistry was pretty non existent between the leads, but I want to attribute that to more writing than an acting issue. Of course, I have to mention the cast did a solid effort with the sex scenes too. I can't imagine it's easy and most BL doesn't give the prologned and more 'in depth' scenes that this movie offers. So...there's that.

Music: Very passable and totally forgettable (and ultimately not necessary to even consider). On a partially petty note, I'll say they overdid it on the classical music scores. I know it's all supposed to be fancy underground clubs and such, but they could've toned it down on the same classical songs playing just about everywhere.

So, overall: there was a great deal of potential that this movie had, but it fell very flat in execution. I think it may have been due to having too much going on and therefore the execution becomes and messy and confused. It would've suited having just one direction chosen and really focusing in on that: either, the student/teacher relationship occuring years after a big life ruining betrayal, or navigating the host scene OR male prostitution. The movie overall could've really used a more focused tone as well: either it's going to be slightly comical or make it dark but whatever it is - pick it and stick to it. The wishywashy nature of the movie really tanks its rewatchability. I'll also add that I'm not sure if this is adapted from a manga...if so, then I guess there is a lot story/direction wise that might be hard to change due to the source material. Even then, i think the tone issue is more a reflection of directorial issues than any manga influence. I did really want to like this movie...it's a real shame.