Eun Ha Won, a high school senior with dreams of becoming a teacher, endures mistreatment from her father, stepmother, and stepsister while working part-time jobs to fund her university tuition. Meanwhile, three spoiled cousins—Ji Un, a tough guy, Hyeon Min, a playboy, and Seo U, a musician—live together in the mansion Sky House, constantly bickering with each other.
When their grandfather orders them to attend his 5th wedding, Hyeon Min hires Ha Won as his date to upset him. However, Ha Won’s bold attitude impresses the grandfather, who hires her as a live-in butler at Sky House. This sparks a series of comedic events, love triangles, and drama.