I decided to watch this! Still didn't really dig the sci-fi thing, but it was doable.
I must say though, I LOVE Ji Hyun and Soo Hyun. Their chemistry is awesome! The way they cuddle and everything is just so natural and....too cute. The scriptwriters are really good at pulling us in with those gazillion kisses! Haha. Love the last one of course.
I was left a little depressed with the open ending, but I wasn't hoping for any fairytale ending, considering he's an alien, so I guess I'm okay with it. I'll just not imagine what life will be like for Song Yi when she grows old and he doesn't.....sad.