Female lead strings male lead along in the beginning

He's in love with her while she thinks of him only as a good friend. She rejects him and he doesn't take it well. She's in love with the second male lead. Eventually starts dating him, but during then she realizes that she wants to be with the male lead and tries to reconcile and get together with him.

A classic of that trope would be Boys Over Flowers or Hana Yori Dango the jap. version as I saw you watched a lot of Jdramas. But I wouldn't recommend the Chinese remake Meteor Garden.

Weightlifting Fairy Kim Bok Joo and Strong Woman Do Bong Soo are 2 others I really like. The romance is super fluffy and carbon-copies of your description.