Jang Keun-suk as Han Joon-soo

Song Ha-yoon as Kim Byul

Moon Mason as Han Woo-ram

Ko Kyu-phil as Ki-seok

Lee Moon-sik as Subway Attendant (cameo)

Oh Kwang-rok as Gwang-rok (uncredited)

Jeong Gyu-su as Kim Byeol's Father (uncredited)

Jang Jung-hee as Kim Byeol's Mother (uncredited)

Kil Hae-yeon as Ki-suk's Mother (uncredited)

Park Hyun-suk as Joon-soo's Mother (uncredited)

Jeon Se-hyun as Joon-soo's Ex (uncredited)

Jeong Min-sung as Drunk Man (uncredited)

Kim Do-yeon as Ordinary Girl (uncredited)

Kim Gu-ra as Room Salon Customer (uncredited)

Lee Cheol-min as Police Officer (uncredited)

Park Myung-soo as Woo-ram (voice) (uncredited)

Song Min-hyung as Teacher (uncredited)

Yoo Ji-yeon as Room Salon Girl (uncredited)

Kim Dong-seok as Doctor (uncredited)