Wai Rai High School(2001)

Original title: วัยร้ายไฮสคูล

This drama takes place in high school where a group of students always pranks their teacher and their class is well known as the worst class. The leader of the group is Aon who is a brave girl. One day a new student join their class, Ryu, who is always moody, alone and most of all hates the group of pranksters.