Lovely story. Yes, a few loose ends for the side characters (one could always hope for a separate volume to flesh the rest of the stories), but I think the ending serves very well for all the build-up to it. This was a more realistic, slice-of-life, coming-of-age story where I never expected the main pair to actually get together. The bittersweet, but ultimately happy outlook shows how many of the characters have grown and matured over a year of drama: resolving oneself, hard work and small victories, heartache, melancholy, and also many brief, unexpected moments of joy.
If you're one of the readers that are mad they didn't get together, I'm worried about your expectations for romance manga (and maybe, by extension, your views on love in real life). There are hundreds if not thousands of stories about couples getting together (go read those; I too enjoy the diabetes, and I get that manga is escapism for many people... it's been there for me to unwind from the day and also gotten me through a lot of tough times), but there's also space for stories like this where we see the considerations and struggles of people in trying to figure out each other and see if a relationship is feasible. There are so many emotional, familial, and social angles for the main couple to work out (not to mention if they'd actually be a long-term good fit for each other), that I'm glad they decided to follow their dreams and not become emotional crutches for each other and run away from their problems. To demand a story turn out a certain way even though what actually happens in the story is reasonable, now that's some entitled, if not delusional, thinking...
Relationships are, after all, a lot of work. And often a lot of coupling don't work out or even happen in the first place. While it was a punch to the gut to see Yoshizawa reject Nishida, I'm glad the author didn't go for the usual trope of the side characters getting together and becoming foils for the main pair. This what-could-have-been pairing instead becomes the chance for one of the goofier characters to grow up and find her own purpose / identity. And I've also met people in real life similar to Yoshizawa and Nishida (may they find happiness in their lives). So while we might hope for a fateful encounter with our soul mate (I happen to believe we might have more than one compatible match...), we most likely will need to put in the effort even if it doesn't always work out.
