Tell Me Something— Full Cast

Han Suk-kyu

as Detective Cho

Shim Eun-ha

as Chae Su-yeon

Jang Hang-seon

as Detective Oh

Yu Jun-sang

as Kim Ki-yeon

Yum Jung-ah

as Oh Seung-min

Ahn Suk-hwan

as Prosecutor Gu

Kim Jung-hak

as Detective Lee

Gil Eun-hye

as Young Soo-yeon

Park Cheol-ho

as Section Chief Yoo

Lee Hwan-jun

as Detective Kim

Kwon Tae-won

as Chae Yong-hoon

Lee Dae-ro

as Chief of Police

Maeng Bong-hak

as Museum Colleague

Kwon Nam-hee

as Soo-yeon's Mother