'' You're an idol?'' ''I was surprised you didn't recognize me when we bumped into each other, even when I moved next door.'' ''Didn't I tell you I only know Girls Generation and BTS? Oh, and IU?'' ''Well, it's never too late to start listening to Seventeen'' ''Well, I guess I am supposed to, Because...'' Seo Min-Young is a regular woman who is trying to secure a job, crosses paths with a man, who if she had known, would be an idol from a group she's going to manage. While getting along with the members, what if she finds out that someone she thought she wouldn't get along with was her brother all this time?