Part 1: Park Seojun

Park Seojun is a girl who pretends to be a boy at a boys's school to figure out about his brother's case (Park Jimin). She got many friends and some of them love her as a donsaeng but not for Jiyong and Seungri. They almost fell in love with her but they thought he was a boy. What will happen at last? Will she reveal everything about her brother's case and HERSELF TO BOTH JIYONG AND SEUNGRI?