"Cutie Pie" revolves around single mother Ok-Suk, who raised her three daughters Lim Ji-Won, Lim Yeo-Jin, & Lim Bonnie on her own. Her irresponsible husband Lim Ha-Ryong left her 15 years ago after declaring for bankruptcy. One day, a divorced man named Kim Seong-Su and his son Kim Joon moves into the same building where Ok-Suk lives. He then decides to marry Ok-Suk's eldest daughter Lim Ji-Won, who is a widow. As her family is now thrown into chaos, Ok-Suk's husband Lim Ha-Ryong has the audacity to suddenly return ...