Recently I watched Just Between Lovers, and I loved it. 

Is there anything similar to this drama?

In the similarity regards, I am looking for something about a big traumatic event, flash backs of being young together and reuniting when they're older. And definitely a romance, and a K-drama.

Thank you.

you should check out the currently airing drama Thirty But Seventeen

The only that comes to mind is Come and Hug Me

As a confirmed drama addicted, i can tell you that all dramas mentionned under has all you wish:

1-Come and Hug me

2-Missing you 

3- Uncontrollably Fond

4- i hear your voice

5- Kill me heal me

(6- Black, this one is kind of different from the overs but still, it has all you mentionned)

Enjoy !

I second:

  • Come and Hug me
  • Kill me Heal me

Also:

  • Healer
  • What's wrong with secretary Kim
  • 20th century boy and girl
  • It's not that I can't marry but I don't want yo

Some meet as children with a deep traumatic past together, ans meet again as adukts aand try to heal ewch others scars:

  • + Healer 
  • +1 come and hug me - this is more sinister and darker in nature
  • +1 kill me heal me - but this is more romcom
  • Will it snow for christmas
  • Angel Eyes
  • My Love Eundong
  • Seven Days Queen