Both are mini dramas in which a couple breaks up due to a misunderstanding, lies, and scheming from relatives. The FL then returns with a stronger, more jaded personality. In both, one of the parents was unaware they had a child or thought the baby died and discover that they now have a five year old child who helps brings the two back together. Both MLs have cruel mothers who hate the FL and try to separate them.
Both are mini dramas in which the couple breaks up due to manipulation by the rich ML's relatives, and the FL, who is poor, gives birth to and raises their child alone. Five years later the couple crosses paths again and begin to grow close, raising their child, all while dealing with the ML's relatives.
Both are about a rich ML and poorer FL who were in love but separated due to scheming from the ML's family/friends. The two reunite when the FL returns 5-6 years later. The ML later discovers the FL was pregnant when they broke up and he now has a young child who he interacts with before realizing the child is the FL's or his. Both have an identical scene where the ML sees the FL working at a nightclub and misunderstands her.
Both are short length dramas with the same actor as the ML. In both the couples are separated for years due to misunderstanding/lies, and then unexpectedly cross paths again, with one of the leads discovering a shocking twist (in LS the FL discovers the ML who she thought was dead is alive and living under a different name, whereas in LE the ML discovers the FL was pregnant and still in love with him when she rejected him those years ago and is currently raising their young daughter).