I binge watched this and i don't regret doing it - i don't think i'd have been able to finish it if i had watched it while it aired.
The plot fits perfectly the definition of my own guilty pleasure; if you've got a thing for spy / romance dramas, then this one is for you!
Although the plot lacked a lot: it didn't bring anything new, the action scenes weren't so spectacular and the characters didn't show much depth.
The thing that saved it all for me was the cast: i fell all over again for park hae jin, kim min jung's acting was fresh and full of cuteness, park sung woong did a really good job at making me get attached to his character and the supporting roles weren't so bad either.
I won't say i'll watch it again but if you've got nothing to do and netflix on, you could probably have a good time watching this drama!