First of all, art was pretty good. I really enjoyed the style, everything was clean, cute and overall nicely done. It lacked details to give it 9 or 10, but it was good.
Now where the bad part begins: the story. Ok, so we have a romance + slice of life manga, so you expect to see a healthy mix of relationship progression with some ordinary every day interactions. And here comes the problem: instead of blending those two ingridients to get a tasty meal, we are fed two separate dishes: first author speeds through main romance line, does it in 37 chapters, and after that we get almost a hundred chapters of slice of life with addition of side character romance subplots.The problem is way too obvious: why didn't author just end Horimiya and make another manga as a spin-off? It is no longer Hirimya, in my opinion, cause focus shifts away from them completely and they get basically no development. And the contrast of chapters 1-37 and the rest of manga simply is confusing, as the change of pacing and content changes are way too significant.
And you know, I could be fine with change of pace, but the characters are so dull to watch, that in all of those chapters they barely had any progress. Closer to the end there were a few good points that could be exploited and used as subplots for a few chapters, but they were just discarded (like Iura's sister). Some side character roots were not even finished and left in a "maybe they will stop being dense and finally go out, or maybe not". While I could get this move in Tsurezure Children, but Horimiya seemed to have a different approach for subplots, and teased the reader too much (if someone rooted for Yoshikawa) just to drop the subplot without doing anything - and that was horribly frustrating. Even for the main couple, neither of main heroes got a good look into their problems. Like how Hori feared about her future and was ashamed of being basically a housewife at home, or how Miamura was so socially isolated and how he feared he could never fit into society - both those topics were slightly mentioned, one of them was used in the last chapters - but it was not developed in depth, it started and concluded too fast without any notable events. And I once again remind you that both those huge problems had any weight in the first 37 chapters and were dropped completely after.
So basically as for me, I got hooked on the first 37 chapters, I waited for the subplots to be resolved and for the main couple to get some interactions, but was fed fillers with almost zero content for years and got a "that's all, we are done". And this leads me to describing this manga in only one word: frustrating. If it was split in two mangas - I would love the first, and would simply drop the second. The problem is that I didn't really know what to expect, or maybe I wanted to get more of the stuff from the begining of the manga only to get nothing and get dissappointed. Maybe I am in the wrong for expecting something, maybe I didn't read the signs where the manga is going but overall I can say this:
all the enjoyment I got from the first chapters was completely ruined by boredom that came next, and transformed into fury after the manga ended before ending the subplots.
