The story revolves around the characters of the Hong family. The protagonist is a girl by the name of HongNanhee, the middle child of a family which runs a taekwon do dojang (equivalent of a karate dojo. She has an older brother, Nanpa, who is the jjang of a technical high school, Gong-goh, and younger brother, Nanmyoung. Nanhee has a second degree in taekwondo, attends a girls’ high school and has a tendency says what she wants to say without realizing the consequences.
When Nanhee’s younger brother was born, she was left in the care of her older brother, Nanpa, who took special care in raising her; he has a sister-complex. He tends to be overly-protective of her: he gets rid of any guys that hang around her by getting her underlings to tail her, making it almost impossible to have any male friends.
Nanhee’s younger brother happens to be in the rival high school his brother attends, Sanggo. He is also a member of the school’s “gang” and often aids JiYoungjin, the jjang of his school.
One day, while out looking for Nanmyoung, who has skipped school, she encounters Youngjin. Nanhee manages to find her younger brother, and they end up quarrelling. The quarrel attracts the attention of Youngjin. When Youngjin sees Namhee, he asks if she wants to be his girlfriend as he thinks she will be useful to him. She flat-out rejects him, and leaves. Her straight-forwardness and lack of tactfulness is what leaves an impression on Youngjin.
After that incident, Nanhee becomes more curious about Youngjin and tries to confront him in front of his school. When Youngjin finds out that that she’s Hong Nan-pa’s precious little sister, he asks his underling Hae-min to find out more about Nanhee. Hae-min is curious with what Youngjin intends to do with Nanhee and asks if it’s to start a fight with Nanpa. Youngjin reassures him that although the thought crossed his mind that, it has nothing to do with Nanpa; he does want to keep her as his toy.
Both Nanhee and Youngjin go through a couple more confrontations. When she bumps into him at a a night club when she’s looking for her younger brother, Youngjin insults her and calls her a fighting chick, using that as her nickname. It would seem that he likes to pester her to get a reaction out of her.
Youngjin’s father is the president of a company, however, not much is known about it except that they have offices in New York. Youngjin was close to his mother, but unfortunately his mother died when he was younger. His father remarried a younger woman, but Youngjin’s relationship with his step-mother is not good: Youngjin has no respect for her, and insults her by calling her “step-mother” instead of “mother” in Korean.
One day, Nanhee decides to check up on Youngjin to see if he’s all right after seeing him get taken away by his father’s men. He drags her with him to a bar, where she gets attacked by an upperclassman from Sanggoh, GohYoonsoo. Youngjin stands by the side and does nothing but watch her defend herself. However, after the incident, he finds Yoonsoo at school and beats him up to the point of hospitalizing him. After dealing with the police, he makes a deal with his father that he would not to get into anymore trouble or else he would have to go to New York to learn the family business.
When Youngjin deliberately starts a rumor they are dating, things become difficult for Nanhee as all the girls start feeling sorry for him and eye Nanhee for it. This starts the war between Nanpa and Youngjin.
Nanhee requests Youngjin not to fight with her brother, but he is dragged out anyway to fight Hyoil, Nanpa’s best friend. While Youngjin and Hyoil are fighting, Nanhee is kidnapped. Nanmyoung manages to find them and tell them that Nanhee has been kidnapped. They desperately look for her and manage to find her with Yoonsoo.
At the sight of Yoonsoo, Youngjin is so upset that he beats him up again. Youngjin’s father forces him to leave for America the next day; how long he stays depends on how much progress he makes out there. He does not tell Nanhee or anyone for that matter where and when he is going. Their relationship and feelings are put to the test while he is away…