Seo Do-gyeom, the master of the mansion, and Yoon Seo-won, the son of the housekeeper. Although it was an unattable relationship, Do-gyeom often stays together as a shelter for the room where Seowon lives. Seowon kisses Do-gyeom, the most perfect being in the world, and falls in love, For some reason, Do-gyeom leaves to study abroad after that. I tried to pass by with a one-man unrequited love. But five years later. The day Seowon became an adult and left the mansion, Seo Do-gyeom returned. "I just need an omega, do you want to do it?"