Kim Yoonhee dresses as a man to provide for her family by copying manuscripts. When the debt collectors up their game, Yoonhee decides to do the same.

Lee Seonjoon arranges for Yoonhee to take the imperial examinations under her brother’s name, but her answer on the test catches the eye of the king.

Yoonhee saves Seonjoon from the upperclassmen’s initiation punishment, but she gets herself into a new spot of trouble.

Classes begin, and Yoonhee attends her very first lecture. Ha Insoo’s hatred of Seonjoon leads him to set his sights on Yoonhee.

Professor Jeong Yakyong stumbles upon Yoonhee’s secret after her rescue. Later, Seonjoon helps Yoonhee prepare for the archery competition.

Professor Jeong tells Yoonhee she must win the archery competition to continue her studies at Sungkyunkwan. Yoonhee and Seonjoon continue training.

Yoonhee’s team and Insoo’s team go head-to-head in the archery contest, but someone is plotting against Yoonhee in the shadows.

Insoo embarrasses Yoonhee in front of everyone. Yoonhee dejectedly heads home, but someone is secretly following after her.

The scholars return to find their valuables missing, and people suspect Yoonhee. The king presents her with a way to prove her innocence.

Seonjoon runs into trouble in his search but is saved from danger. A vital clue helps to finally reveal the identity of the true culprit.

The king’s investigation takes a surprising turn. Yoonhee opens up to Seonjoon, who says he wants her to stay by his side.

Seonjoon and Yoonhee spend a night stranded on an uninhabited island. Seonjoon struggles with his emotions. Moon Jaeshin and Yoonhee grow closer.

Yoonhee tries to mend her relationship with Seonjoon, but he reacts coldly. Seonjoon and Jaeshin clash over Yoonhee.

The rumor that Yoonhee and Jaeshin are lovers spreads like wildfire. Yoonhee thinks Seonjoon started it. Insoo calls for an inquiry.

After the inquiry, Seonjoon drops out of Sungkyunkwan and decides to marry Ha Hyoeun. But before he does, he confesses his feelings to Yoonhee.

Seonjoon is shocked to find out that Yoonhee is a girl. He tries to convince her to drop out before her secret gets out, but Yoonhee wants to stay.

In hopes of reforming Joseon, the king gives the group a secret mission. As they work to solve a mystery, Seonjoon and Yoonhee share their feelings.

Seonjoon is stunned by his father’s implication in the incident. He looks for the one witness who can reveal the truth, but the trail goes cold.

When Jaeshin is injured, Seonjoon names himself as the Red Messenger. Yoonhee leads the student body in an attempt to save Seonjoon.

The king accepts the students’ petition and releases Seonjoon. Yoonhee receives the king’s thanks for her efforts. Insoo learns Yoonhee’s secret.