What's Up?

Lim Ju-hwan

Jang Jae-Hun

Oh Man-seok

Sun Woo-Yeong

Kim Ji-won

Park Tae-Yi

Im Joo-eun

Oh Doo-Ri

Cho Jung-seok

Kim Byung-Gun

Kang Dae-sung

Ha Do-Sung

Jang Hee-jin

Eun Chae-young

Lee Soo-hyuk

Lee Soo-bin

Ahn Seo-hyun

Oh Doo-ri (young)

Song Ok-suk

Jang Jae-heon's mother

Kim Mi-kyeong

Professor Yang Soo-jung