The rating of 9 is a bit relative. I would not compare it other shows with similar ratings ("Flower of Evil", "Beyond Evil", etc).
I based my rating on:
- was it fun to watch: definitely yes!
- was it hard to not press the "Next" button at the end of each episode: also yes!

The show's atmosphere swings between serious thriller and comedy in a pretty unusual manner, but it's well done.
The story is interesting and well acted, and because of the humorous tone, you forget about the things that you would pick on in a classic mystery.

Give it a go!