Working-class girl Geum Jan-di winds up at an exclusive prep academy and teams up with the popular boys of F4, who literally rule the school.
Just being rich isn't enough to survive the teen tyranny at Shinhwa – outsiders or loners are often marked as targets by the bored über-clique F4.
A scandalous rumor is spread on the Internet that a second-year student at Shinhwa High School, identified as "Miss K," is pregnant.
Not keen to watch Jan-di dancing with one of his best friends, Jun-pyo leaves the ballroom and ends up taking out his frustrations by the poolside.
Making a sudden decision, Jan-di tells her mother she has to go somewhere and runs off, heading toward Namsan Tower.
Jan-di's bike is set on fire while she is assaulted with water balloons and blasted with a fire extinguisher.
A psychic predicts that Jan-di will be losing something important.
Jun-pyo plans to evict his best friend and Jan-di out of Shinhwa High School – and out of F4.
Jan-di rushes to the hospital after hearing that Jun-pyo has been in an accident.
Yi-jung receives a hysterical call from his mother threatening to commit suicide because of his father.
Valentine's Day reveals hidden feelings. With the family dry cleaning business in serious trouble, Jan-di decides to take a new job.
A note indicates that class has been moved to the science lab. The lab is empty, but Jan-di waits, not noticing that the room is filling with fumes.
Jan-di's father gets taken away by loan sharks, which inevitably forces Jan-di's mother to swallow her pride and beg Madam Kang for help.
The F4 guys have moved on to university, while Jan-di has entered her final year of high school. She has not heard from Jun-pyo since he left.
Jan-di waits to hear the results of F4's meeting with Jun-pyo, and can tell from their expressions that it was not good.
After treating Jan-di in a harsh manner, Mr. Jung prepares everything so that Jun-pyo can see her in Seoul. Can he go without Madam Kang finding out?
Jan-di's family hears about Jun-pyo's engagement and asks her dejectedly if it's true.
Ji-hoo can see how hurt Jan-di is by the kiss, and continues to follow her as she walks around in a daze.
Jun-pyo starts seeing Jae-kyung in a different way, like he's seeing her for the first time as a potential friend – or maybe a kindred spirit.
Woo-bin tries to talk some sense into Yi-jung, who is hell bent on drinking himself into oblivion.
At home, Jun-hee thinks back to how her mother interfered in her life, in much the same way she's interfering in Jun-pyo's now.
Yi-jung is happily waiting for Eun-jae, until he accidentally overhears her phone conversation, which sounds like she is talking to a boyfriend.
Jun-pyo pleads for Jan-di to tell him not to get married.
Jun-pyo tells Jan-di that he'll protect her, but to Jun-pyo's surprise, she says that she does not want to be protected or taken care of.
Feeling it's time to reveal the truth, Mr. Jung leads Jun-hee to the mystery patient's bedside, and at the sight of her father, Jun-hee breaks down.
Jun-pyo asks Yumi to make the lunchbox again, proving that Yumi had taken credit for the lunch that Jan-di had made for him.