After going through training to overcome bullying, a high school teenager who has had problems with his life and his relationships in school must face a bully on the first day school.
| Actor | Role |
|---|---|
 Bong Tae-gyuNam Kong-dal | Nam Kong-dal |
 Zin Tae-hyunYeon-seong | Yeon-seong |
| JJeong Yoon-joMin-ah | Min-ah |
 Ha Seok-jinJae-koo | Jae-koo |
| CCheng YunMan-chang | Man-chang |
| SSeung-yeol ChaTae-chang | Tae-chang |
| CChang-ju SinWangkeul's Doctor Kim | Wangkeul's Doctor Kim |
 Baek Soo-jangNot listed | Not listed |
 Choi Eun-juMae-soon | Mae-soon |
 Chu Sang-miFemale Doctor | Female Doctor |
 Son Byung-wookTae-son | Tae-son |
| HHong Kyeong-yeonKong-dal's Mother | Kong-dal's Mother |
| JJeong Dae-hoonStudent on bus | Student on bus |
 Lee Je-hoonAhn-Kyung | Ahn-Kyung |
 Jo Dal-hwanByung-goo | Byung-goo |
 Lim Jeong-woonBiology Teacher | Biology Teacher |