Jeon Do-yeon

as Yun Hong-yeon

Lee Byung-hun

as Kang Soo-ha

Lee Mi-yeon

as Yang Eun-Hee

Song Ok-suk

as Yun Hong-yeon's Mother

Kim Jae-in

as Nan-hee

Seo Hye-rin

as Teacher Yu

Lee Dae-yeon

as Teacher Jo (uncredited)

Kim Seon-hwa

as Bum-soo's Mother (uncredited)

Park Kwang-jin

as Kim Joo's Grandfather (uncredited)

Lee In

as Soon-cheol (uncredited)

Lee Young-hoo

as Bookstore Owner (uncredited)