Why R U?: Reparto
Lee Jung-min
Jung Lee Won
Lee Sang-min
Woo Sun Woo
Park Chang-hoon
Ko Yu Gyeom
Lee Ye-hwan
Kim Ji Oh
Jeon Sa-ra
Kim Do Yeon
Jo So-young
So Young
Dawon
Da Won
Park Young-un
[Yu Gyeom's Junior]
Kim Na-hyun
[Professor]
Su Hyun
Jung Lee Jin [Lee Won's Sister]