Female lead travels back in time to save the guy she loves. Very melancholic, both are set partially in adulthood and partially in youth

30 but 17 is a romantic comedy about a 17 year old girl who gets into a car accident and spends 13 years in a coma. When she wakes up, she has to relearn how to live life as an older woman. Diva of the deserted island is about a woman who spends years on an uninhabited island and has to relearn how to participate in society.

Both are melodramas and deal first-hand with the topic of illness, and both dramas use it as a mechanism to cause conflict but also cause the leads to become closer. If you enjoyed the exploration of illness in either drama, you will enjoy the other one too.