Lee Minhyung is known to be heartless. And Lee Donghyuck is curious. One wrong step and Donghyuck is in trouble with none other than Lee Minhyung himself.

Lee Donghyuck is laidback, funny and hardworking and recently started working as the assistant to the CEO of Lee Enterprises, who is known as Mr.Lee. Life seems to be all unicorns and sunshine to Donghyuck until Mr.Lee unexpectedly retires and his son takes over the company. Donghyuck now has to face a new challenge. A challenge known as Mark Lee.