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

김강현

Webtoon editor

Seo Hyun-chul

Deputy Department Head Seo

최대성

Taxi driver

염동헌

Department Head Uhm

김민규

Male college student

옥주리

Kim Sun-Kwon

서우진

Interviewer

윤진이

Jo Suk's old friend

Lee Su-ji

Interpreter

박경혜

Ae Bong's friend

Kim Min-ho

Jo Suk's friend

Song Joong-ki

Webtoon writer / Jo Suk's friend

김세정

Woman next door in Room 205

Jang Hyo-jin

Director

이재은

Lee Ji-Soon

Ban Hye-ra

Middle-aged wife

주부진

Grandma Kim Jeom-Rye / Deok Hwan's mother

서진원

policeman

강균성

Jang Nam-Chul | Kyun Sung

정이랑

Kim Yoon-ji

김숙

Kim Sook

박나래

Jo Suk's old friend

Seo Jung-joon

Jo Suk's classmate

금광산

Jo Chul Wang's subordinate

Kim Roi-ha

Mex / Kim Nam-Chul

김민경

Club woman picked by Jo Joon

이세영

Jo Joon's lover

Son Young-soon

Grandma selling gum

정준영

man next door in room 205

김태원

Self

신동엽

Self

전현무

Self

박슬기

Self

Jung So-yeon

Self

배진예

Self