Episode 4 S01 E04

Yoon Kye-sang (as Cha Min-hu) Seo Ji-hye (as Hong Ye Sul) Kim Ji-seok (as Lee Pil-yo) Lee Ju-yeon (as Oh Ji-young) Tae In-ho (as Oh Seung-taek) Kim Ga-eun (as Ban Ho-woo) Hwang Bo-ra (as Jang Um-ji) Kim Mi-su (as Kim Min-hee) Kim Ki-doo (as Kang Sang-gu) Yoon Jung-hoon (as Kim Ro-ma) Yoo Jeong-ho (as Yeom Kyung-Seok) Kim Jae-hwa (as Jo Sun-hee) Kim Hee-jung (as Kim Sa-ra) Uhm Hyo-seop (as Kim Hae-jin) Moon Woo-jin (as Cha Min Hoo [Young]) Lee Ro Eun (as Hong Ye Sul (Child)) Kim Kwang-shik (as Cheol Yeong [Sa Ra's boyfriend])

based on novel or book workplace office romance supernatural power secret