Basically, how do I ensure the reader will want two characters in a romantic relationship?
Sorry about the wall of text in advance and I won't blame anyone for giving advice on the general topic instead of reading the whole thing. It's all good to me.
The focus of the story won't be on romance and there will be no romantic relationship between the two characters. Rather, the protagonist will look up to a mysterious character to the point of it seeming like a crush.
The pseudo love interest will become a main character halfway through the story and there will be hints of the protagonist's feelings not being one-sided but ultimately their relationship is left open to interpretation.
I need the reader rooting for the main character in pursuing the love interest. The reader should yearn for more interaction between the two. The climax of the (hopefully subtle) romance arc will align with a major turning point in the main story: there will be a choice, the protagonist will choose the love interest over something important and this will change the entire story. It's a huge mistake, even unjust, but it's vital that it feels good to the reader!
The first problem I have is that the protagonist meets the love interest a bit late in the story and I'm not sure how to introduce an important character and make him likeable ASAP. I've decided to fix that by moving most of his backstory to the beginning of the whole thing. We'll see him as a child before the first set of main characters is introduced, then he'll make a couple of major appearances as an adult but we can't tell it's him yet – I just need the protagonist idolizing him based on their few interactions.
I can't for the life of me figure out how I should play this romance arc out and find a balance as to not make my approach too subtle or boring without getting obnoxious or plainly bad either.
Source: reddit post