What's in each episode:
1. At first, the drama is not so interesting. It shows some women working as "entertaining" women. They smoke and drink beer, a job that is considered illegal in South Korea. Nothing really interesting in episode 1. You gotta hang on to it.
2. You start to understand what is this drama about: A student running a secret-modern-remote security service where he is unknown to his employees and clients.
3. Romance stuff kicks in, but it's not overloaded.
4. Conflicts intensify.
5-8. You really enjoy the drama because of how stupid the characters are to solve their problems.
9. You start to think about how this drama ends.
10. The conflicts are still on fire that you now look for the ending. Some are somewhat satisfied (like me) and some are unsatisfied.