Yoon Shi-yoon

Baek Se-jin

Yeo Jin-goo

Lee Byung-joo

Cheon Ho-jin

Seok-gu

Lee Kyung-young

Principal

Park Sang-myeon

Byung-joo's father

Lee Won-jong

Jong-hee's father

Kong Jeong-hwan

Jeong-hwan

Kim Bo-mi

Yi-hwa

Yoo Seo-jin

Anna

Je Dong-hwa

Gang of Four