The Sound of Your Heart

Lee Kwang-soo

Jo-Suk

김대명

Jo-Joon

Jung So-min

Choi Ae-Bong

Kim Byeong-ok

Jo Chul-Wang

Kim Mi-kyung

Kwon Jung-Gwon

Song Joong-ki

Webtoon writer / Jo Suk's friend

김세정

Woman next door in Room 205

김강현

Webtoon editor

Seo Hyun-chul

Deputy Department Head Seo

염동헌

Department Head Uhm

Jang Hyo-jin

Director

이재은

Lee Ji-Soon

Ban Hye-ra

Middle-aged wife

최대성

Taxi driver

주부진

Grandma Kim Jeom-Rye / Deok Hwan's mother

서진원

policeman

김민규

Male college student

옥주리

Kim Sun-Kwon