Oh Hyun-jin is a high-achieving career woman who becomes the oldest mother at Serenity, an elite postpartum care center. Despite her professional success, she finds herself completely out of her depth when faced with the physical and emotional toll of childbirth and the intense, competitive social hierarchy among the other mothers at the facility. As she navigates the challenges of motherhood, Hyun-jin forms an unlikely bond with the other women, including the 'Queen Bee' Jo Eun-jung. The series explores the complexities of parenting, societal expectations, and the transition into motherhood with a blend of dark comedy, satire, and heartfelt drama, highlighting the struggles that are often hidden behind the facade of perfect parenting.