The Queen's Classroom follows the story of Ma Yeo-jin, a cold and calculating elementary school teacher who takes charge of a sixth-grade class. Unlike typical educators, she employs harsh, unconventional, and often cruel methods to teach her students about the harsh realities of the world, effectively turning the classroom into a hierarchy where the students are pitted against one another. As the school year progresses, the students—led by the resilient Shim Ha-na—begin to challenge Ma Yeo-jin's authority. Through their struggles, conflicts, and eventual growth, the students learn to stand up for themselves and each other, while the mysterious past of their teacher is slowly unveiled, revealing the tragic reasons behind her rigid and cynical philosophy on education.