Golden Pouch- The male lead is an orphan who lost his memory when he was a kid and has been searching for his parents ever since, he does find them towards the end of the drama.
Ojakgyo Brothers- the male lead is left with his aunt and uncle when his mother abandons him, he ends up meeting his brother towards the end but he doesn't actually meet his mom again, there is closure though.
Smile, Dong Hae- The male lead's mother is the one who gets separated from her family during a storm, they reunite towards the end of the drama.
Pan Ruk Pan Rai as well as Lady & Liar- are both about female leads who thought they were orphans but in are actually long lost heirs to important families, then on the way to being reunited they get amnesia.
Golden Bride- female lead's father just abandons her and her mother to go back to his family, she becomes a mail order bride in order to go and find him.