Knock, Knock! Please Open Your Heart

Park Bo-young

Yoo Mi-ji / Yoo Mi-rae

Jinyoung

Lee Ho-su

Ryu Kyung-soo

Han Se-jin

Jang Young-nam

Kim Ok-hee

Kim Sun-young

Yeom Bun-hong

Won Mi-kyung

Kim Ro-sa

Cha Mi-kyeong

Kang Wol-oon

Lim Cheol-soo

Lee Choong-gu

Lee Jae-in

Teen Yoo Mi-ji / Yoo Mi-rae

Park Yoon-ho

Teen Lee Ho-su

Jang Se-hyuk

Choi Seung-hyeon

Moon Dong-hyeok

Song Kyeong-gu

Yoo Yu-jin

Park Ji-yun

Hong Seong-won

Kim Tae-i

Jung Seung-kil

Choi Tae-gwan

Lee Seung-joon

Yun Ji Sang

Min Sang-cheol

[Doctor]