Rather than Drama, this story should be classified as either Psychological or Tragedy.
CAUTION: It's not an exact spoiler as I'm refusing to to talk in details but reading the rest will make it very easily to sus out the incoming developments of the story.
The main antagonist (who also seems to be a lot of readers' favourite) (unsurprisingly) is hard-carrying this story. He is the only one with a story [arc]. He has a backstory, cards stacked against him, choices to made which he made wrongly . . . I would say twice (or actually countless more, but two are the eventful ones) but only one choice mattered so maybe just one . . . and that doomed him to his bad ending. That's called Tragedy. Through the process he did grow and made the right choice at the end, which resolves his story arc.
On the other hand, the two other main characters did not have such interesting story arcs.
The protagonist did have his past with the main antagonist, but that only added to his depth and not really his growth. When their story concluded together it only felt as if the ending that has been postponed has simply come . . . so easily. There seemed to be no pay off. The protagonist was not shown to be struggling with his choice. He made a decision, the main antagonist did not accept it, and at the end he made it again with his words clearly this time, and this time the main antagonist did. That's it. Drama is a bust.
For the protagonist's storyline with his other love interest, it also was not interesting. The love interest had no depth to his character. His love for the protagonist is just plot. Love at first sight. Love epiphany in a wet dream. He was your good-ish guy taking care of someone he was interested in. There was no drama. There were obstacles, but they were all external. The obstacle even turned into a semi-growth moment for the protagonist. Romance is a bust.
By the way, love at first sight + love epiphany in a wet dream is really all the development for the (main?) love interest.
This brings me back to my main point, and that is the main characters except the main antagonist are super uninteresting.
The protagonist had barely a story arc with his final acceptance of love and not just pretending everything is just friendship. But where is the growth? He just met the same choice again, and regretted his past choice and made a different one. Ok, yes, that is something but we didn't even get a reason why he made the wrong choice in the past! No such obstacles came into making the right choice now? So whenever that choice came again he would have made the right choice because the wrong choice was only to be made once and he learned? Where's the story?
The love interest has even less of a story. He did not struggle with his feelings. His minor transgressions to the protagonist in exploring his feelings aren't addressed by the plot (which is fine, but also it does not make him likeable). That was his only flaw and he did not get anything from it. Again, where's the story?
If the author wanted to explore the themes of SA (as someone who has been in enough situations . . . yes, you can call it grape, I still think you should not call it grape but SA), they should have made that transgression more than a non-issue.
Overall I think the author made two interesting characters, but they did not put enough effort into developing one. And the overall plot was just as expected, as things should be, that is, predictable.
Unlikeable protagonist is a sin. Had the protagonist have more flaws, homophobia perhaps, the root of that perhaps, which gets addressed as part of the plot, it would have been better as a story.
This is simply unsatisfying. Thought-provoking perhaps, but unsatisfying. Happy guy got the good thing he deserves, not interesting. Unhappy guy reached, sinned, got the punishment he deserves, that's ok. Uncaring, indecisive, now traumatized guy, got a happy-ish ending without much growth? Doesn't seem so deserving.