Kim Young-jae (actor, born 1975)

Oh Jae-geol

Do-hee's father

Kim Pil: Se-eum's overly dependent husband who seems to be affectionate and considerate, but feels inferior to his wife due to her success. Jin Geon-woo as young Kim Pil

Kang Hyun: a senior manager.

Chief Royal Secretary Min Seung-yun

Nam Moo-young

Jin Yoon-ki

Jung Joon-il, Vice Chairman of Sungjin Electronics and Seo Han-sook's son.

Lee Jeong-woo, in early 40s

Ko Moo-won, Moo-chi's elder brother. He is a priest temporarily housed in the basement of a church. When he was young, he was saved from being killed by a serial killer, but has become disabled since. He is isolated from his younger brother Ko Moo-chi. Jo Yeon-ho (ko) as young Ko Moo-won

Moon Kyung-hoon

Kim Min-suk

Kim Tae-jin (Ep. 28–29)

Eun-cheol, an ornithologist.

Kim Kyung-soo (Ep. 2)

Ji-woon's father

Kong Gil-dong

Doctor (ep. 1, 2)

Shin Se-ki

Psychiatrist

Park Moon-soo

PD Byun Hee-sool

Han Jae-hyung

Kim Chang-ho

Kang Mok-soo

Choi Young-ho

Choi Min-young

Jo Tae-sub (Mi-soo's older brother)

Na Seok-jin, Hee-soo's assistant and Na-hee's lover

Kang Min-gu, Bok-gu's brother Joo Min-soo as young Min-gu