Kim Nari who is from a rich family was supposed to be in the most prestigious school in korea goes to a normal mixed boarding school but pretends to be a boy for a reason. Her brother Kim Jongin goes to the same boarding school but is a senior. Her roommate Park Jimin is a cute boy but is manly in his own ways. Why did Nari pretend to be a boy? What will happen to her relationship with her ' best friend ' Park Jimin when he finds out? What will happen to her