I would like to start by saying that I blame the director. All my major problems with this series basically boil down to the director not directing properly.

Premis is a forbidden romance I can get behind.
Bodyguard falling in love with the boss's son.
Love & duty on the line.??

For the most part even though the mc starts off as a little spoiled brat, he does get better as it goes on.

The bodyguard is just kinda sad with his kind of adoptive father taking advantage of him the way he does. He is generally good if a little stoic most of the time.

I liked the 2nd couple, they were funny & cute and really deserved a more well developed story than what they got.

The mob bosses and their henchmen were okay. I laughed at them more than I probably should have but they weren't terrible..

The acting overall was okay until the more emotional scenes which is when the director needed to direct the actor better because his acting went from decent to...
The emotional scenes just fell flat coz I couldn't get past his acting which again someone should've flagged & helped.

It was rehearsed, shot multiple times, edited and reviewed and NO ONE thought that maybe they should re-shoot those scenes after giving some helpful feedback to the actor? No one?

In conclusion: Direct damn it. He wasn't a bad actor, he just needed better direction!