Not sure what happened. Bad writing? Young director? Small budget?

As others have stated there are continuity issues:
- Let's have lunch to celebrate our first day together! Boss guy takes over ordering and mentions that everybody orders the same thing each time. But, this is their first time as a team. Desserts purchased. What happened to lunch? Translation issue?
- Coffee spilled on shirt. They almost take off their shirts but, never do. Yet - after dinner - it's mentioned he has his boss' shirt on and needs to return it. And, between the shots of when it happened and during the discussion of squishy and soft - the shirt becomes magically clean.
- Gossip from the interns about everything you would expect but, none of it comes to pass and there are little repercussions. One gets talked to and, everyone gets hired. Why was it even there? Tension wasted.

Not enough backstory and development of the characters. We know they got separated and the lead up was one set of parents fighting but, the other kid ends of moving away and while there is brief mention of why he chose not to contact - it doesn't float. Why would he feel responsible for leaving? Did his parents surprise him and he couldn't say goodbye?

Jun Eonni had a wonderful backstory that we only get hints of. Feels he isn't good enough to be loved. Doesn't realize what a great person he is. Is afraid of getting close to someone for fear of them leaving. But, we see almost none of it. We get the explanation of why the manager cares so much but, why explain it like that when there is love there?

Jun Director had a cliche backstory but, we see and barely hear of what he went through. Is he job determined because he was lonely? How can he be such a successful flirt if he kept to himself all these years? It's true that his drive and stumbling along show he needs to communicate better but, my guess is his fiancé helped him as a person to grow and learn how to be around people.

Surprisingly, product placement needs some work. While the wonderful The Wedding Plan snagged The Arches and more - this one seemed to forget who was paying their bills. In a way - that is good but, were the check writers satisfied?

I had to restart watching this twice to catch on to what was happening. I figured out the flashbacks, caught the conversation, and really paid attention. If you only watch it once through - you may end up being confused but, still happy at the overall story.