Despite her dismal grades, Ra Eun-ho sets her sights on getting into a prestigious college. Hyun Tae-woon rebels against his father.
While Eun-ho investigates to find out who really trashed the teachers' office, Shim Kang-myung does what he can to try and clear her name.
The headmaster tells Eun-ho that he'll withdraw the penalty if she finds the notorious Student X. She keeps close tabs on her two suspects.
Eun-ho faces detention for trying to break up a fight between Tae-woon and Song Dae-hwi. Oh Sa-rang sees this as an opportunity to spy on Student X.
While her well-to-do classmates use influence to pad their extracurricular records, Eun-ho has to figure out how to complete hers on the cheap.
Even after catching him red-handed, Eun-ho chooses to give Dae-hwi the benefit of the doubt. But Tae-woon is unwilling to let this one slide.
When it's revealed that the math competition was rigged, Tae-woon loses everyone's respect. Dae-hwi receives a proposition he's too desperate to refuse.
Eun-ho and Tae-woon lie to protect Dae-hwi, leaving him to make a choice. If he decides to come clean, he'll have to risk his future.
After an awkward moment in the rain, Tae-woon and Eun-ho attempt to avoid each other. A rumor keeps Kim Hee-chan on edge.
Despite being accused of school violence, Eun-ho manages to gain the support of her classmates. She tries to get an important witness on her side.
Hee-chan comes close to finding out the truth when he tries to trap Student X. Eun-ho holds on tight to her dream, but hits a wall.
After exchanging a few punches, Tae-woon and Dae-hwi finally have a heart-to-heart. Hee-chan threatens to reveal Student X if he doesn't get his way.
Eun-ho admits her feelings toward Tae-woon. When students come down with food poisoning, Student X heads to the cafeteria to investigate.
Student X manages to escape the headmaster who, now more eager than ever to catch the culprit, turns to Sa-rang for information.
When his father finds out his secret, Tae-woon worries someone else will take the fall. Hee-chan's mother gets involved in the chase for Student X.
Tae-woon and Eun-ho face expulsion. In order to allow Eun-ho to go back to school, Tae-woon makes a deal with his father.