Doctors.

They are one of the busiest people ever on the planet Earth and out of all, Park Jimin is one of them. Serving as a part of the crew in the ER Department of Seoul Hospital, Jimin is always devoted to his work and he spends most of his time in the On Call Room. All forms of entertainment of his are put on hold and you would describe him as a really boring person.

On the contrary, Kim Donghyun is a cheerful and optimistic girl who is well-liked by all. Finally achieving her doctorate from overseas, she has now returned to work under the Pediatrics Department in Seoul Hospital. With her outshining personality, her appearance is deemed to make a difference to Jimin's life but there lies a problem. 

Park Jimin exceptionally despises her for no reason and he even claims that he will never ever show any interest to her, for the fact that, his eyes has always been set on the one and only person he has had a crush on for years - Bae Joohyeon, four years his senior who also works under the same department as him.