Main male characters both have the same condition of hyperthymesia, remembering their past lives in vivid details and using that as their ability to overcome their difficulties and challenges coming their way.

They have the same actress. Both of these has made me cried a lot, very touching. Their meanings are very different, but I still recommended this because both of the storylines, to me, are very good and meaningful. Even though Dong Yi is a long drama, once you watch it, it will keep you asking for what's going to happen next and you'll keep watching it until you'll know it ended. I like Dong Yi more than Iljimae, because Dong Yi is such a inspirational drama to me.