Yeon Shi-eun is a model student, who ranks at the top at his school. Physically, he appears like a weak boy, but, by using his smarts, tools, and psychology, he fights against violence that takes place inside and outside of his school.

• Park Ji-hoon
• Choi Hyun-wook
• Hong Kyung
• Lee Yeon
• Shin Seung-ho
• Kim Su-gyeom
• Yoon Jung-hoon
• Hwang Sung-bin