Not sure why this drama is rated as low but personally I've seen worst drama that as higher ratings than this. I would describe this drama as a light-hearted romance comedy.

Pros: The leads are visually appealing and the acting is good and the music/soundtracks are memorable. The over-the-top antics of the 2nd leads may or may not appeal to you.
Cons: There are no real depth to the story so if you are looking for some life-changing lessons or etc then this is not the place for you.

Personally, my wife and I enjoyed this very much. Overall, I would say I had a good time watching this and have no regret's on the time spend on this.