Title:
I kind of had an idea why the title was called 'Stains' just by the description, which is good since it means the title is actually connectable to the story, and it's not a bad title. I think short titles can have just as much of an impact as longer ones (I like shorter titles honestly) and it fits. So overall, decent title.

Description/Foreword:
The description wasn't enough to make me want to read because of the fact that it sounds kind of... generic. The whole "Bangtan crew" and "rebel" things are so overused with BTS as a whole, really. I've seen it all at this point and I do remember reading a story where BTS were rebels that did graffiti so the idea itself doesn't seem very original. But really, it's hard to actually make something 100% original these days, huh? Even I can't at this point, my brain is dead from trying.

Not only that but holy shiznit, why are there so many pictures? It makes it like a scroll down galore. Maybe I'm the only one who thinks having pictures of the characters is obnoxious, considering you won't see "character charts" in books and such, but these photos are pretty big as well. It's almost overwhelming. The real focus is the OC and the main character, not everyone else. Not even that but now I feel like there's gonna be A LOT of characters to try and keep up with and while books do have several characters, I hope the focus stays where it should.

Plot:
Considering how many chapters there are and how huge the word count is, I'm not reading all of it. So, if something has changed or has been fixed, please note that I haven't read all of it as that is a lot to read and I don't have the time for all of it (it's almost 3am).

First impression is that everything is a bit much. What I mean by that is the huge font for the "quote" or lyrics, whatever that is; it doesn't really need to be that big. Also, the soundcloud link isn't really necessary since it just makes everything look sloppy to me. Also adding another soundcloud link in the middle of the story is kind of... obnoxious? I mean, people are there to read the story, not have that stuff thrown at them. Plus most people will probably listen to their own music while reading. Nice pictures for each chapter though, I like them.

Honestly speaking, this review was hard to do because I felt myself cringing at the point of view (more down in writing style) and I couldn't bring myself to read it and "soak" it in. Your writing is good, don't get me wrong, but the point of view just makes it so weird.

Anyways, from what I saw, it does seem kind of cliché and generic. I mean, I've seen stories like this and it doesn't really get me excited. They go to the same school, the OC is the sister of one of the guys, etc. It's all been done before. I just don't see myself getting into this because of the genericness and the point of view, they're both things that make me go "eh". 

Maybe it's because I didn't read all of it, and honestly I couldn't read the second point of view much more, but it was flat. The plot's conflict isn't clear at the moment to me and I don't know if it's supposed to be early on in the story; probably not. Considering it's a series, I hope the other stories don't effect this one because then everything might be way more complicated but it doesn't seem like it does.

Writing Style/Flow:
The first, huge, problem to me was the point of view. Second point of view is the worst in stories for me to read and just feels strange. "You" just doesn't work with me much because it makes me feel legitimatey awkward. First point of view isn't the best to read either, as third point of view is the best, but I'd prefer it over second. I've never liked the feeling that I was in the story because the story isn't about me, it's about two characters; the OC and the main guy. But I just feel like it's about me now and it's making me legitimately feel awkward. So the point of view made it hard to read for me. It makes me feel like someone is writing my life for me and I don't know, it's just really weird. 

As I said, your writing is good and this story is good for people who can tolerate "you" stories, which I really can't, so that made the story iffy for me. So it's definitely not that you're a bad writer, you're not - you're probably better than I am lol - it's just the point of view. While some parts I could read without feeling awkward, mainly because it was "he said" parts, the story would have been better in third point of view. Instead of "you", maybe "he, she, etc" and the OC's name would have been a bit better.

I also noticed that, specifcially in the first chapter, there were times where two character's dialogues would be merged into one. 

EX: "It's okay. I understand." You nodded and smiled. "Hoseok can be kind of... unpredictable somtimes." He scoffed. "Yeah, that's for sure..."

Two characters are talking here and that's a big no. Doesn't matter how short the dialogue is, always seperate. It's hard to read when two people are speaking in one paragraph because it can be confusing. I had to do several double takes because of it so yeah, maybe you should take a look into that because it's done A LOT and it's just confusing. Kind of gave me a headache to process who was talking (doesn't help I'm still up).

Characterization:
This is hard to talk about because of the point of view. I just feel like I'm having stuff thrown at me. "You were never the shy, apathetic type." That's literally the only way you can know the character OC because with 'you' fanfics, it's hard to process the character (for me at least) since the only way you can learn personality traits is through things being told. I think the characterization just kinda slipped over my head. I feel like the only thing I know about the "OC" is what we're told through the "you" stuff.

For Jungkook though, his character is kind of... eh. So many people seem to make him a bit of a prick, like you did in the second chapter, and then later on, he usually becomes nicer and yadda yadda. So I felt like he was falling flat because of his generic characterization. Most people seem to make certain characters have a certain personality. Such as Kai from EXO being a playboy in a lot of stories or Sehun being a grumpy brat. The stigma around these people are so annoying because it's just overused. The stigma that Jungkook is a brat, or is perfect, or is a prick, are very much overused from what I've seen but then again, I don't read OC fanfics unless I am asked to for reviews.

Personal Enjoyment:
Definitely not something I'd read. First of all, everything is just not my taste; the generic plot and concepts, the second point of view, the oc story, just not for me. The dialogue was a bit of a headache to read at times because of the fact that more than one person would be speaking in several paragraphs throughout several chapters; definitely look into fixing this problem. But, for what it is, it's not bad. It's just not for me personally. The word count is ing impressive though, like how the did you even manage to write that much? I can't even write close to that much for like a 50 chaptered story so that's very impressive to me.

Tbh I think I forgot how to review stories since my mind legit has an "overwatch tard" stamped on it. If you need help trying to understand my non-english, but english, review, please let me know. I don't know what I'm doing. (Plays "What Am I Doing?" parody by Malinda K Reese since theme song and really, what am I doing?)

....I apologize that you have to deal with this mess of a reviewer for even a minute.