"Naughty teenager" is a story about Ha An - a top student in school both academically and physically, but is also called the "stubborn student". One day, Ha An fell into love and found herself pregnant. At that time, she devoted herself to achieving a scholarship to study abroad, which would help her get away with the gossips. Ironically and unfortunately, life rolled her into endless obstacles. Ha An was expelled from the school, turned away by her family and disparaged by her friends, all because of her pregnancy. She was harshly forced to a dead end and had no other choices but commit suicide. However, could the timely presence of Mr. Phong bring Ha An back to life?