Seo Yian is a butler at a prestigious hotel where the elite of the elite frequent due to their unmatched service, but more importantly, for their all beta staff. Yian is just another one of those betas, serving as a personal butler for VIP client Yoo Jekwon. Yoo Jekwon is an alpha and a CEO of his own company. He is on a whole other level to most people, but especially to Yian, who feels lucky just to be in his presence every day. Jekwon is mysterious, pretty much living at the hotel. But Yian isn't going to look a gift horse in the mouth and instead takes full advantage of Jekwon's odd living situation.
To take their working relationship to the next level, Yian offers some “special services” to Jekwon. Though Jekwon is initially surprised, he happily accepts, and the two spend many steamy evenings together under the guise of a master-and-servant relationship. Unfortunately, after spending Jekwon's rut in his bed, Yian takes in a lot of alpha pheromones. This has the unfortunate side effect of forcing Yian into a transformation, causing him to manifest into an omega. While this would give Yian the chance to be with an alpha like Jekwon, it means he can no longer work as a butler, a job he adores. Jekwon is more than happy to take responsibility, but with Yian's pheromones being unstable, their relationship status undefined, and the threat of Yian's identity being exposed to his job, Jekwon has his work cut out for him.
All of this is only made worse as Jekwon's stepfather is determined to find any weakness Jekwon might have and exploit it to force his stepson to work in his company.