Lee Jung Hee is the second daughter of a family who owns a lingerie factory. She leads a group of teenage girls, whom they have chaotic adventures together. She meets Bae Dong Moon through a group date and Dong Moon immediately falls for her. However, Jung Hee has a crush on Son Jin who is a cute looking senior student of a boys school and begins to follow him around to draw his attention.
Then one day, Park Hye Joo who is a transfer student from Seoul joins their class and becomes the center of attention, creating jealousy and friction among the heroine and her friends. Despite Jung Hee's attention, Son Jin is attracted to Hye Joo. However, Hye Joo has no romantic feelings for Son Jin as she is interested in Joo Yeong Choon who is an ex-gangster now turned to a local handy-man.
It's the story of their growing friendship, as the heroine and the new girl starts to bond despite the initial rivalry. There's also a darker side to the story, with a mystery surrounding an increasing number of sexual assaults in the city. And at the local toy factory, female workers begin disappearing one by one.