18 Again - really enjoyed this one. It has fantasy in it where the ML turns into his younger body but it's not as cringy as it sounds. Very heartwarming and surely worth a try.
Can We Get Married? - the main couple starts off wanting to get married, so they already have an established relationship. There is also a second lead couple that is amazing!
Fated to Love You - I will put this here cause it kind of fits. It has the arranged marriage trope but there are a lot of scenes where the couple is together and they have amazing chemistry. It will pull at your heartstrings for sure
I Need Romance - fits your criteria really well, and I loved it!
I Need Romance 2 - you don't need to watch the 1st one to see this, cause they don't have anything to do with each other. The themes and how they are handled are similar. It deals with an on&off relationship between the main leads. Both the 2nd and 1st seasons have amazing chemistry between the leads and more of a mature feel than your typical kdrama.
ISWAK & TKA - it's a Taiwanese drama that has 2 seasons. In the 1st one you will watch how they get to be together and the 2nd season deals with their married life! Really good, have been rewatching those for like 3 times already :))
My Wife's Having an Affair this Week - the couple has been married for 8 years
Ojakgyo Brothers - one of the best family dramas that I have seen. One of the couples deals with the trope you mentioned (they were also my favorite one). Hwang Tae Beom and Cha Soo Yeong have been married and now want to divorce, but a lot of things happen along the way. This is a really amazing drama!
Hope you will find some to your enjoyment!
