First of all, kudo for the writer to try something new. This drama is not your typical Korean drama. The story is very unusual and unique (as expected from tvn, usually they make unique drama). It has quite a start slow but it built the story to be very funny. Once they turn into grandpa, the story becomes very funny. This drama is more a comedy focus, so forget to have a serious criminal case. The story is lighthearted and great to watch to pass some free time, in addition, you get to see Hee Chul to!  The cases are all very predictable. I think sometimes the comedy is overdone that makes the drama weird.  I think this drama has some potential to get better.

The is a plot twist in the middle. Then the story becomes too predictable and typical a little bit melodramatic k drama. And I fall for 2nd male lead... Sigh.....