In the Joseon era, Kim Yoon-hee masquerades as a boy to earn a living as a book transcriber. Her family's dire circumstances and the encouragement of a noble's son finally drive her to attend Sungkyukwan University, forbidden for females.

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.—K.W.

Kim Yun Hee is a smart, responsible young woman with an independent drive. Since her father passed away she has worked to support her family, but also managed to do well in her studies. When her younger brother's illness worsens and their family is in danger of being evicted from their house for lack of money. In her desperation to support him, Kim Yoon Hee decides to take the men's only national exam under her younger brother's name and disguises herself as a boy. On the day of the exam, Kim Yun Hee meets Lee Seon Joon and becomes friends. Lee Seon Joon comes from a privileged background and also possesses good looks. He is also arrogant. They both pass the national exam and she has to share a room together with him at Sungkyunkwan University while hiding her true nature. There, she becomes friends with the playboy Goo Yong Ha and rebellious Moon Jae Shin.