This establishes the "vibe." Is it a clash (Enemies to Lovers) or an instant pull (Soulmates)?
Here is a deep review of the mechanics, the pitfalls, and the evolution of romance in narrative. 1. The Core Engine: Conflict and Chemistry
The "Romeo and Juliet" factor—war, class divide, or meddling antagonists.
A romantic storyline succeeds when it feels If the characters are only together because the script says so, the audience feels nothing. If they are together because they are the only two people who truly "see" each other, the story becomes timeless.
The breakup or the realization that the relationship is impossible. This forces the characters to change or sacrifice something to be together.
Contemporary stories are moving away from romance as a "prize" to be won.

