Yoseob is a rich guy who has everything. He's got money, he has the looks, and even his own personal maid, IU. She's been his maid since they were 12. I know, a young age huh? Well her family owed a huge debt to Yoseob's family so they gave IU to them instead. IU has never once asked for anything from their family even though his parents treat her like a real daughter. But this time she asks for something. One thing. To be precise she wants to go to school. They didn't let her go to school when she was younger since her job was to take care of Yoseob and house chores. And even though this was the only time she asked for something they rejected. Not wanting to be found out, she sneaks out of the house early in the morning and late at night to go to classes. The downside is that she always walks there. Sometimes she runs but only if she has the energy. The reason being why is because Yoseob's family doesn't pay her. They never thought to, considering she's always stayed inside the house. But what happens when Yoseob caught her going out? How will IU make him keep her secret?