Manager Kim was an ordinary head of a household with a daughter and lived as a small citizen. In order to find his daughter, who is his everything, he reveals a secret that should never be revealed to the world.
I like South Korean series, but "Agent Kim Reactivated" is, simply put, awful. In my opinion the primary shortcoming is the scripting. This is supposed to be an action thriller, yet it's almost as if they are reluctant to get on with telling the story. Instead, there are incessant, irritating asides and shifts in story and focus; pointless secondary characters by the bushel; combined with a wholly unbelievable, overstated, super-humble-to-the-point-of-absurdity "doormat dad" who apparently is also, and this is the funny part, a secret agent/ruthless assassin.
Acting is decent, but that's this series' only saving grace and a meagre one when you consider all that doesn't work as it should.
In summary, a lack of focus in the script, combined with implausible characterisations, ruins what could have been a great series.