This is a historical drama about the girl Kim Yoon-hee who has taken her sick brothers identity to be able to work and fend for her family. By chance Yoon-hee is accepted into the Sungkyunkwan university and there she gets to know Sun-joon, Jae-shin and Yong-ha. The quartet find themselves in the middle of a political fight for power, both between the students as well as their parents. During all of this Yoon-hee must keep up the appearance of being a man, which gets increasingly difficult as time passes and feelings start to develop between the friends.