Both drama are about divorcees ending up with each other. One More Happy Ending has a ton of divorced characters, but in Emergency Couple, I believe it was just the main couple.

In both dramas, the two main leads have the same fears. And you'll see what happens when you watch them.

Both main girl and main guy had a relationship that didn't workout in the past, but they meet again... and you can prob guess the ending.
Plus, they both have a lot of past flashbacks.