I watched the movie version, and I heard it has more scenes than the series version, so that's a plus.
The story is simple and good, the actors are great, overall this show is great. But, the thing that stands out the most is their song. I LOVE their song to pieces; Wish You by Kang In Soo and Lee Sang. That first scene with them supposedly singing together is just breath-taking. I've been listening to it for a month now, sometimes on repeat for hours and I still love it. It is just beautiful and make me feel happy and in love.