I'm a sucker for stories where Character A has unrequited love for Character B and they do everything they can to win Character B's love to no avail, then it suddenly switches and it suddenly becomes B desperate for A to return THEIR feelings.

Any recommendations of manga/manhwa with this as a major plot point? Any genre is fine with me, but a few examples off the top of my head:

Skip Beat!

BJ Alex

Ouran High School Host Club

I Don't Love You Anymore

A Painter Behind the Curtain

Painter of the Night

The Ten Years I've Loved You the Most

What It Means to Be You

Nodame Cantabile

Your Majesty, Please Spare Me This Time

Thank you for the help in advance!

Toradora!
Watashi ni xx Shinasai! - The 2nd couple
GE - Good Ending
School Rumble

Anime - Just Because! (12 episodes)

Rokkon Shojo
TeppenMezashiteTondeAruYo
Let justice be done, though the heavens fall