I will tell you why this all happened. There are 2 types of 'romance' tags in manga.
1) romance: There is virtually no development or progress at all in the RELATIONSHIP of the 'MC COUPLE'. What do I mean by that? Most of the manga is about wishy washy back and forth between MC and MC girl and maybe some other GIRL(s). They never reach the point of going out, making up, making hard decisions, etc etc.
THIS is what the author gave us, instead of making them a true couple ages ago, it was only done "surprise* at the END of the fucking story. Well fucking clappity clap mother fucker you just wasted all of our time.
2) romance: The development is done THROUGHOUT the manga. Relationship is formed early or even at the beginning. The MC couple have to struggle together through various life difficulties or even their own short comings. Drama with other people trying to break them up or maybe past relations, etc. Now this is a fucking manga, there is probably making out, but mostly some pretty basic hugging, kissing shit, but some will have sex onscreen/offscreen, etc etc.
I, my own personal opinion consider 'ROMANCE' when there is a fucking actual couple and shit actually happens. I fucking despise the "oh and now they going out at the last chapter because we were too fucking lazy on their development!" which is how most of these shitty tags end up like.
You are more than welcome to agree to disagree.