So, this is my first review. I'm happy to be losing my reviewer virginity to sadism herself, Nagatoro-san.
(This review is a review of chapters up the the current one: ''Chapter 13: Nope, This is Senpai's Drawing'')

If you want my overall score without having to read the entire thing, here it is:
-Story 7/10
-Art 10/10
-Characters 6/10
-Enjoyment 8/10
-Overall 8/10

First of all, I know this manga is not for everyone. It can be hard for people to make it past the first 6 chapters (especially those with a history of being bullied, because Nagatoro does make Senpai cry and then mock him for it). But after chapter 6, it gets better. Not that chapters 1-6 are bad, they're just sad really. So if a manga about unrequited love and a sadistic girl (who occasionally isn't a sadist) doesn't sound good to you, maybe skip this one.
But anyways, onto the review.

-----Story: 7/10-----

The story here is decently written, but it's a slice of life manga so naturally every chapter is disconnected from the others with the only connections between them being the characters (e.g a scene isn't going to start in chapter 7 and end in chapter 8). The main driving point of the story is that it's unique. I can't think of a manga or anime that has a story similar to this.

The basic idea is that our Main Character, the unnamed 'Senpai', is a lonely, flustered, otaku boy who enjoyes reading fanservice manga and spending all his free time alone in the art room. So if you're on MAL chances are you can relate to this character. However, when a dark skinned, wide eyed first year girl called Nagatoro picks up one of his drawings he dropped, a typical shonen boy saving a hot girl from danger, she dedicates her school life to making his life miserable (or maybe she's trying to do something else). So why does he put up with her? He has a crush on her. Unfortunately for our pubescent hero, it doesn't seem mutual. So while it's tagged as a romance, it's pretty one sided and hidden (the only signs we get that he loves her is a few panels scattered around the manga and the description).

Other than the concept alone, the story isn't too interesting. Each chapter is a new environment and a new situation with no overlapping arcs or story connections (e.g. Nagatoro is making fun of Senpai's art on the way home from school, Nagatoro is teasing Senpai in the Art room, Nagatoro is calling Senpai her pet in front of her friends in the Canteen).

-----Art: 10/10-----

By far my favorite part of this whole manga is the art. The artist nanashi (or 774 House) nails the often embarrassed and flustered facial expressions of his characters, perhaps from his experience in.... other genres. I'm talking NSFW, Lolita,Thrown-In-Jail-For-Degeneracy style genres, including one called ''Naked Honey Kana Fire 2 Monkey Copulation with Landscape Species''. So take that however you want to.

Anyways, if you've been on r/animemes on reddit, no doubt have you seen some art from this series, including the extremely popular (and my desktop background) juice box meme
[http://i0.kym-cdn.com/photos/images/original/001/347/678/3e9.png]

The art here is phenomenal, the stuff of memes. Like many others, I find myself screenshotting and cropping every single panel to use as reaction picture images. I cannot fault the art, it's amazing


-----Characters: 6/10-----

Oh boy. Since there are only two important characters in this manga, I rated each one out of 5 and added them together to get my final score.
-Senpai: 1/5
-Nagatoro: 5/5

Lets start with Senpai. He's boring! He literally is only interesting when Nagatoro is bullying him and hes failing to stand up for himself. He doesn't even have a name! He literally has nothing going for him, except how he looks adorable when bullied by Nagatoro. He's a lackluster, self loathing teenager who's self confidence is lacking and spends all his time alone in the art room. The only good thing about him is, as I said before, his face is very reaction image/profile avatar-able. But, coming from a doujinshi artist, I suppose good male characters aren't a strong point.

Nagatoro-san is great. Unlike most of the other characters like her, who are just stubborn and tsundere, Nagatoro seems to genuinely not have a romantic interest in Senpai and instead derives pleasure from emotionally beating him up (and sometimes physically). However as shown in Chapter 6, Nagatoro isn't naturally like this. When she's not around Senpai, she's a cold, uninteresting character who shows no emotion (when listening to music, she simply says 'I just didn't feel anything' while looking depressingly at the table). The fact that she's so emotional and bouncy and mean around Senpai means she is attached to him in some way, as he seems to be one of the few people she feels emotion around, so maybe there is a chance for some spicy romance. Nagatoro's bullying actually does take a turn around chapter 7 where she switches from just bullying him to bullying him to make him more confident (e.g. Forcing him to compliment her, Forcing him to draw her and then blueballing him, Relentlessly insulting him until he figures out a comeback).

-----Enjoyment 8/10-----

I enjoyed reading this manga so much, it's so bubbly and bouncy and oozing with charm. The only parts I didn't enjoy were the first few chapters where Nagatoro is just a nameless girl who hurts Senpai so much he starts to cry. Other than that though, this manga is so damn fun, and I'm so excited for more to come out and (Hopefully) an anime adaptation (maybe with the harassment toned down).

-----Overall I'm giving this manga an 8/10-----
-The first few chapters can be hard to get through
-Everything past the first few chapters is great