Alright, so I think you might be talking about 'Marriage of Convenience'? If so, there are a few main characters. The protagonist is usually Elena. She's often described as sharp but trapped by her family's expectations or a debt. Then there's the male lead, often named someone like Kaelan or Marcus. He's the cold duke or CEO type, bound by some old family rule that forces the marriage. Their dynamic drives everything—initial hostility, slow-burning tension, forced proximity. You also can't forget the best friend, someone like Livia, who provides the emotional support and comic relief. Sometimes there's a scheming ex-fiancée or a rival who tries to sabotage things, adding drama. Honestly, the names and exact titles blend after a while because the tropes are so similar across this subgenre.
What I find most interesting is how the 'forbidden' element plays out. It's rarely about the marriage itself being illegal. More often, it's forbidden by social class, by a family feud, or by a secret one of them is keeping. The tension comes from them having to hide their real feelings or the real reason they're together, even from their own families. The supporting cast, like a wise grandmother or a loyal butler, often sees through the act first. It's a fun, predictable comfort read, and the characters are designed to hit those specific beats of angst and eventual romance.