Lee Seung-gi

as Kang Joon-soo

Moon Chae-won

as Kim Hyun-woo

Lee Seo-jin

as Lee Dong-jin

Jung Joon-young

as Andrew Yeom

Go Yoon

as Jae-joong

Park Soo-young

as Min-ah

Ryu Hwa-young

as Hee-jin

Sieun

as Joon-hee

Ha Kyoung-min

as Han Seong-goo

Park Eun-ji

as Cha Myung-sun

Im Ha-ryong

as Principal

Kim Kap-soo

as Joon-soo's Father

Lee Kyung-jin

as Joon-soo's Mother

Song Young-chang

as HQ Chief

Kim Bu-seon

as Hyun-woo's Mother

Lim Jong-yun

as Director

Kim Kwang-kyu

as Bald Man

Hong Seok-cheon

as Restaurant Owner

Lee Ju-yeon

as Joon-soo's Girlfriend

Kim So-yeon

as Joon-soo's Ex-girlfriend 1

Son Ga-in

as Joon-soo's Ex-girlfriend 2

Park Ji-yeon

as Weather Woman

Lee Dong-jin

as Staff

Park Hee-gun

as Joon-hee's Boyfriend

Hong Hwa-Ri

as Young Hyun-woo

Lee Young-bum

as Military Instructor

Cho Young-joon

as Young Joon-soo

Lee Young-beom

as Military Assistant Teacher

Nam Neung-mi

as Baths