Subtle but Strong Romance

It's hard to explain, but the best example I can think of is of Rebel: Thief Who Stole The People. Romance wasn't the leading genre and neither was it very apparent, but just from the nature of the lead couple's relationship and from their interactions I couldn't help but ship them very hard. It didn't feel like they were together because they were the leads, but it was more like they were together because they fit each other's personalities and characteristics. Chicago Typewriter kinda fits the bill as well, but the romance wasn't as quite as memorable as Rebel's.

A few requirements: A happy (not open) ending and no love triangles unless it's minor and doesn't take over the romance for the rest of the show.

*When I mean subtle, I don't mean something that hints at a romance. Romance still has to be a genre, I just don't care if it's a side or main genre.

 Sorry if my request is too hard, but I've just been craving something like this for a while now.

Maybe try Hello Monster or Ms. Perfect? In both cases romance isn't the main genre and the leads get a happy ending, although some of the secondary characters have a sort of open ending. In Ms. Perfect there's arguably a love triangle, but it's more just that the father of the FL's kids stays involved in her life, not that she's really romantically torn between him and another character. I wouldn't call the person she ends up with the ML. He's essentially the second male lead, but for me he was the main thing I enjoyed about the drama. 

 AH:

Maybe try Hello Monster or Ms. Perfect? In both cases romance isn't the main genre and the leads get a happy ending, although some of the secondary characters have a sort of open ending. In Ms. Perfect there's arguably a love triangle, but it's more just that the father of the FL's kids stays involved in her life, not that she's really romantically torn between him and another character. I wouldn't call the person she ends up with the ML. He's essentially the second male lead, but for me he was the main thing I enjoyed about the drama. 

I've been thinking about watching Hello Monster for a while now, so I think I might try that. I might watch Ms. Perect as well, but I'm not too sure because I prefer watching dramas with younger characters. 

 mahiba:

Rich man, poor woman  (J-Drama) should be right up your alley if you like J-dramas. There's definitely romance and we can see the characters torn by their feelings but it's kinda subtle. Happy ending for the main leads. 

I'm not opposed to watching J-Dramas, I just haven't found a really good one yet. I've heard great things about Rich man, Poor Woman, so I think I might watch it when I get enough time.

I think K2 fits what you're looking for. The main focus of the drama is action and the romance develops more towards the end. 

I think you would like Because This Is my First Life, the romance it's there, subtle. You can find the romance in the main leads couple and in the side couples, it's really great , this drama save my drama year, my favorite of last year by far. :)

 SarahEm:

I've already seen it, but I didn't like it that much. I got bored of it fast and to be honest, I didn't really ship the lead couple all that much. Thanks anyway.

Don't worry about it, :) funny thing , I dropped Rebel: thief who stole the people, it was boring for me, but hey not everyone has the same taste in dramas, right. hope you find something good to watch. :)