Story:
The writing is consistently good from beginning to end. There were no plot holes or overused tropes in this drama. The story flows naturally and it will take you on a roller coaster ride of emotions. It is a family drama. It depicts the reality of life; the struggles of marriage out of high school due to teenage pregnancy, the breakdown of a marriage, the distant relationship between parent and kid, and so on. It even has some funny aspects that will surely make you laugh. It is perfect all around.

Cast and Characters:
I'm not familiar with any of the actors in this drama except for Kim Ha-neul. One of the strengths of this drama is how good the acting is. The lead actors, and even the supporting cast, were all fantastic.

Music:
I loved all of the OSTs. It all fits perfectly based on the theme of this drama.

Overall:
This one is an exceptional drama. It is a must-watch.