Melody of Golden Age - Arranged marriage, they're kind of enemies to lovers. She slowly wins him over, without trying, and he finds himself falling for her first, but he doesn't reveal his feelings to her right away. But about what you're looking for specifically, there's a moment towards the end of the show where they are in an openly loving relationship, but he has to act like he doesn't like her anymore, to protect her from the villain, and that's very heartbraching for him. He has to win her over again after x)