Saika Gasai

As the devoted wife of Ushio Gasai and the adoptive mother of Yuno, this pivotal figure plays a crucial role in the series' darker narrative. Though she appears only briefly, her actions serve as the primary catalyst for Yuno’s psychological breakdown and eventual descent into madness. Her complex domestic relationship with her family provides the essential foundation for the tragic, unstable motivations that drive the story's central antagonist.