Twenty-eight-year-olds Seon Tae-hyung and Woo Hyun-jin find their lives upended when they are forced to raise their infant nephew, Woo-ju, following the sudden death of the child's parents. Despite being in-laws with no prior close relationship, the two begin living together to care for the baby. As the inexperienced pair navigates the challenges of parenthood, they grow closer and begin to develop romantic feelings for one another.

Bae In-hyuk
Seon Tae-hyung

Roh Jeong-eui
Woo Hyun-jin

Park Seo-ham
Park Yoon-seong
Park Yoo-ho
Seon Woo-ju

Oh Hyun-joong
Kim Ui-jun

Oh Se-eun
Ye-eun
Kang Ae-shim
Park Ae-ja

Kim In-kwon
Bae Doo-sik

Han Ji-hyo
Kim Ji-hyun
Lim Sung Jun
Lee Jae Min

Jin Seo-yeon
Amy Chu

Ku Sung-hwan
Jo Mu-saeng

Yoon Woo
Oh Seung-taek

Choi Gyu-ri
Baek Se-yeon
Kim Seong-jeong
Jo Gyu-jeong