This review is based totally on this adaptation. I have never seen any of the others or read the manga. What I like about this drama is that it is easy to watch. There are no villains and the adversity that the characters face is resolved quickly. The story isn't new or special. However, I enjoyed the over all good feeling that I felt while watching the characters grow as they faced trials and over came obstacles both personal and as a group. I don't usually enjoy lot of characters and side stories, but in this case it seemed appropriate. I'm so glad the writer didn't make Cha Yoo Jin too much of a jerk or Seol Na Il stupid. Also, I like that Yoo Jin pretty much takes care of Na Il from the start even if it subconsciously. I don't know how much this varies from the original, but I like this version. I have never seen Shim Eun Kyeong in anything else, but I couldn't picture anyone better for this role. She was totally adorable as quirky, naive and genious Na Il. I know not everyone is a Joo won fan, but I love him. He has played a variety of roles and doesn't disappoint as Yoo Jin. It seemed real as he fumbled around learning to have friends and care for people. The other actors are good also. Go Gyeong Pyo is good as Il Rak. The music is outstanding. It is worth watching this drama for that alone. I will probably rewatch this at some point. No matter what genre you enjoy, I recommend this drama. It is a comfortable and easy watch.