FifthView
Vala
You might be thinking love story, which is not the same thing.
A love story with a happy ending is a romance, that's the proper definition, not me splitting hairs.
I'm not so sure about this, although I'm fascinated by the idea of a love story having a particular structure or expectations that are different from a romance story.
Personally, and not to screw down too deeply into my own subjective metrics....The word "romance" implies activity and endeavor. At least it carries this connotation for me. One romances another. A romance story, then, has this set of actions meant to accomplish an endeavor–building a particular kind of relationship when none existed before. A pas de deux [or trois, heh!] The action is all about achieving that happy state of union.
A love story can be about the love but without that same kind of effort and/or intention. For one, in some love stories the two people might begin the story already in love. In another type, the two parties might be falling in love naturally as the story progresses, not aiming for it, contemplating it much–i.e., not really romancing each other. And there can be other stories in which the surface plot is revealed to be incidental, maybe even in truth merely a subplot, as we come to understand that the story was really about love? I'm stretching here, trying to remember various impressions of different love stories I've encountered in the past. A love story about a long-time spouse descending into Alzheimer's would not necessary have a sad ending even if the situation is sad, but rather could be uplifting and reaffirming of that love in total effect. Hmmm.....