I'm not sure what I expected from this. I hadn't really heard anything about it, just seen some memes and stereotypical "lewd" faces, so I guess something borderline hentai was what I had in mind.
After checking it out, it does feel a bit like reading hentai for the plot, but also surprisingly much more.
I have no idea about the author's intensions making this manga, but I do feel like it is misunderstood at least a bit. The first handful of chapters are about a girl (Nagatoro) picking on and being a general nuisance to a nerdy guy (Senpai) in the year over her in high school. Slowly, we get to experience their unusual (and granted, pretty toxic) relationship through these two so thoroughly flawed characters.
Nagatoro is insufferable on the outside, but we can see her actually slowly diving into this relationship and getting invested. There is no doubt in my mind that she is using her flawed ways to show affection towards Senpai, and that she is much more into him that she admits to herself. We see her façade falter at times, and for whole chapters she acts more or less respectfully without seeming to pay it any mind. To further this, we see her experiences with other males - those who try to hit on her she absolutely demolishes, and not in the playful way she does with Senpai.
Senpai on the other hand was a complete shut in who clearly doesn't have many friends and doesn't speak up for himself. Nagatoro drags him out of that bubble a bit, and he ends up hanging with the hot girls at the beach, walking with a "date" at the fireworks festival, spending time after school with a group of girls, etc. After a while he starts speaking up more for himself, though not enough to prevent Nagatoro's antics obviously.
There is a very meta micro story arc where Senpai draws a manga where the MC is a self-insert. Nagatoro comments that it's unrealistic because Senpai wouldn't act that way in those situations. She proceeds to create a situation to exemplify how he *would* act. It feels to me that the author of Nagatoro is taking some very meta self-criticism by actually creating a pretty pathetic character who acts naturally as he would. (Though not necessarily that Senpai is a direct projection of the author)
To me, the manga is more about Nagatoro's shortcomings and insecurities and how her taking that out on a nerdy guy slowly lets us explore *her* psyche and coming of age, and it has surprisingly more character development than I expected, but it only happens some tens of chapters into the manga. Some of the gags are also pretty good, and the art is obviously top notch coming from a hentai artist.