Characters
Hwang Baek-hyun (Yoo Seung-ho)
Hwang Baek-hyun is a stubborn and reckless rebel and also a tough opponent of Gang Seok-ho.
Yoo Seung-ho
Kim Pul-yip (Ko Ah-Seong)
Kim Pul-yip is sincere but short of patience and tricks.
Gang Seok-ho (Kim Su-ro)
A harsh trainer passes down study skills to enter Cheon-ha University.
A former juvenile delinquent-turned-lawyer, he comes to take care of the liquidation of Byeong-mun High School which is on the verge of bankruptcy. Looking at the inferior students who are lost in Byeong-mun High School, he decides to save the school.
A harsh, cold-blooded, and heartless trainer, who is in charge of a special class for Cheon-ha University applicants, he stretches out his ideas on education.
Han Su-jeong (Bae Du-na)
An English teacher insists study 'for the students and by the students.'
She is an English teacher of Byeong-mun High School. She is a born teacher and regards teaching as her vocation. She loves students hoping to make a school which all the students can have fun studying at it. Having been with Gang Seok-ho for a year, she learns by herself what a 'real' teacher is like.
Hong Chan-du (Lee Hyun-woo)
Hong Chan-du is an inferior student who dreams to be a singer.
Na Hyun-jeong (Ji Yeon)
Na Hyun-jeong is carefree and only cares about Hwang Baek-hyun.
Oh Bong-gu (Lee Chan-ho)
Oh Bong-gu is timid and has no opinion for himself.