Green Mothers' Club follows the lives of five mothers who meet at a prestigious elementary school in a competitive neighborhood. Each woman carries her own secrets and insecurities, navigating the complex social hierarchy of the 'Green Mothers' Club' while dealing with the intense pressure of their children's education and their own personal struggles. As their lives become increasingly intertwined, the facade of their perfect lives begins to crumble, revealing hidden agendas and past traumas. The series explores themes of motherhood, friendship, and the dark side of academic obsession. Lee Eun-pyo, a newcomer to the neighborhood, finds herself caught in the middle of the group's volatile dynamics, particularly with the charismatic and influential Byun Chun-hee. As the women confront betrayal, infidelity, and the consequences of their choices, they must decide whether to continue competing or find solidarity in their shared experiences.