Jang Keun-suk

as Han Joon-soo

Song Ha-yoon

as Kim Byul

Moon Mason

as Han Woo-ram

Ko Kyu-pil

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)