안녕, 형아

Park Ji-bin

Jang Hani

Bae Jong-ok

Mum

Park Won-sang

Dad

서대한

Jang Han-byul

최우혁

Wook

Jeon Hye-jin

Hani's teacher

Oh Ji-hye

Wook's mother

이승훈

Wook's father

Son Young-soon

Wook's grandmother

조영관

Park Jun-tae

Lee Hang

Doctor

Choi Jin-ho

Doctor Na Young-soo