Brave Citizen

So Shi-Min (Shin Hae-Sun) was a promising boxer during her student days. She now works as a contract teacher at a high school. Her only goal is to become a tenured teacher at the high school. To accomplish her goal, she maintains her tunnel vision and ignores troubling situations at the school. Nevertheless, she confronts Han Su-Kang (Lee Jun-Young), who frequently gets into fights and is the most troubled student at the school.

Source: AsianWiki