You know all those shows where the second female lead or minor character will be the male lead's first/former love in the past. Someone he never got a chance with. She got with someone else. Are there any where that person is the female lead and the male lead finally does get the chance years later and ends up with her?

https://mydramalist.com/2687-the-bean-chaff-of-my-life There are comments there, including mine.

  • In Time With You - they were classmates in HS and grow up to be bestfriends, but the ML has been in love with FM for the longest time. But they grew as adults being in different relationship. It also has the korean version which I personally dropped and dont recommend (The Time They Were Not In Love)
  • Hogoo's Love - The ML has had the biggest unrequited love with the FL in HS, but they soon grew to adults pursuing their dreams, they meet again coincidentally.
  • One More Happy ending - ML has been in love with the ML since they were kids, then they go their separates way until they meet again in adulthood
  • Reply 1997 - ML super super liked the FL, he did have a chance somehow but circumstance had them move on separately after he confessed
  • May Queen - korean mmakjang drama that has that plot though this one is very long and most of the times draggy storyline due to its more makjang genre
  • Refresh Man - they were highschool classmates who were at opposite side of spectrum thus tend to clash, but secretly the ML likes the FL
  • Love Now - taiwan drama where the ML an unforgettable and magical encounter with the FL years past, yet never saw her again. They meet again after FL is fooled by family that she is dying, so that she will be forced to go on vacation. ML & FL ended up being 'Married' to fulfill some of her bucketlist,

Dramas where the FL is the ML's first love, but they don't get together until the ML gets a second chance years later (in some of these the FL does not date someone else in the meantime):

  • I Need Romance 3
  • Weightlifting Fairy Kim Bok Joo
  • My Secret Romance
    • The leads meet as adults, but the ML has been a playboy up until that point
    • They have a one night stand (her first) and he falls for her / she's his first real love, but she disappears the next morning and they don't meet again for three years
  • Doctors
    • In the beginning the ML is the FL's high school teacher, so he doesn't pursue a relationship with her, but he gets a second chance when they become colleagues years later
  • The King's Woman
  • When I See You Again

The ML and FL have a childhood connection and based on your interpretation the FL might be considered the ML's childhood / first love:

  • It's Okay, That's Love
  • Just Between Lovers
  • The King in Love
  • General and I
  • Strong Woman Do Bong Soon
  • I Hear Your Voice
    • the leads first meet when the ML is a kid, and the ML is still in high school during the drama

And I second In Time With You.