No love triangle kdrama is very hard tp find, so with the description of drama plot you are looking for here are some With love Triangles, or with another character liking one of the main leads:
- Angel eyes - ex-highschool sweethearts
- Will it snow for christmas - FL first pursued ML during their HS years, when he finally accepts her confessions, she rejects him due to some tragedy
- Winter sonata - in a relationship in HS, then guy was thought dead, buy just had amnesia and new identity
- Wild Chives and soy bean soup: 12 Years Reunion- in a relationship in Highschool
- Uncontrollably Fond - they meet in their teenage days, and were in a 'some' kinda relationship but was separatrd due to some circumstances
- My Love Eundong - sweetest childhood sweethearts, and became a couple in their young adult years, then separated due to accident and amnesia
- Missing You - had strong connrction whrn they were in their highschool years, and thrn tragedy and separation struck
- Love story in harvard - meet each other in their college/grad school fays. They were somehow intetestedt in eacg other but something happened and the FL left
- My strange Hero - they were highschool sweethearts until the ML eas accused of something and expelled from school
- Was it love? - ML and FL were college sweethearts until they broke up and was separated
- Stairway to heaven - MCs are childhood sweethearts that was separated and with FL having amnesia
- Delightful Girl Chunhyang
- Tree of Heaven
- Sangdoo lets go to school
- Age of Innocece
- Wonderful Days
- Sad love song
- All in
- Stained Glass
- Radio Romance
Kinda No Love Triangle, and couples are not really exlovers, more like both were not able to verbalize their feelings:
- Come and hug me
- Hogoo's Love
- Reply 1997 - childhood friends, separatrd after confession falling out
- Cinderellas sister