Yoona is a bad and badass high school's girl. She don't like to mingle with her classmate. She always came to school late and often been punished by her teacher but she don't mind at all.   Taeyeon is the class president. She is a serious and hardworking student. All teacher and student love her. One day the homeroom teacher ask Taeyeon to friend with yoona. But unfortunately, Yoona is a difficult person to approach..   How will Taeyeon do to approach Yoona...