Honestly I also like the trope exactly as you described, I even watched some good dramas based on the trope but right now, I have a hard time remembering the names of the drama.
Cupid no Itazura (The leads are best friends, girl likes him although she denies a lot, but he has a girlfriend, he isn't confident in having sex, whenever he has a argument with his gf, he always goes to her for help. And one night, they end up being intimate.)
Full House (Thai version is my favorite)
(Here both leads pretend to be in love to make his ex jealous)
Ugly Alert (Second couple. Girl is in love with the guy, he is too right, like a stone, always righteous prosecutor so her any advances don't work on him. She tries so hard, but he says he has feelings for her cousin.
She doesn't give up, so instead they end up having a contract dating relationship where they date for a month so that he can prepare himself for his future lover since he doesn't have any experiences on it.
He's really so tough in heart matters, says they need to progress slowly and slowly. He says he'll hold her hand after a year, kiss her after a year but in few weeks, he ends up kissing her suddenly. Lol, he got so worried after that...rest you can see on the drama.)
Birth of Beauty (He teaches her how to be beautiful, how to take revenge on her ex husband, in the end, he ends up falling for her himself. I LOVED their story!)
Miss Korea drama also follows kinda same troupe as Birth of beauty.
Kuzu no Honkai (Mature Japanese drama where they're both in love with someone else and sleep with each other just to forget the one they love. In the end, they end up falling for each other.)
I'll definitely recommend more if I remember more names!
Little Cherry:
