Yuriko Nishinotōin, a third-year Hyakkaou Private Academy student, serves as head of the Traditional Culture Research Club and a former Student Council member. She stands out with her meticulously maintained traditional image, opting for a white-and-red floral kimono over the school uniform, paired with long brown hair secured by a vivid red bow. Her closed eyes, occasionally depicted as brown in adaptations, contribute to her enigmatic presence. Maintaining an aura of serene elegance, Yuriko strategically deploys her composed demeanor to control high-stakes gambling scenarios, notably in her signature rigged game "Life or Death." Though framed as innocuous, the game leverages calculated risks and her family’s financial backing to tilt odds in her favor. This façade crumbles under unpredictability, as seen when Yumeko Jabami exposes her cheating, nearly stripping her of club leadership and council status. Her fierce dedication to preserving the Traditional Culture Research Club fuels her political maneuvers, including a bid for Student Council presidency that falters after Midari Ikishima defeats her in Rock Paper Scissors Poker. Her expertise in cultural artifacts surfaces in *Kakegurui Midari*, where she assesses a tenmoku teabowl’s value and risks her standing to protect it from destruction, later using it for tea ceremonies. During the Hundred Devouring Families arc, she allies with Midari to resist Kirari Momobami’s destabilizing gambles but struggles against Rei Batsubami’s interference and Midari’s impulsiveness. Poisoned by Miyo Inbami and Miri Yobami during a match, her health declines, leading to hospitalization. The prequel *Kakegurui Twin* depicts her defending her council seat against challengers like the Ougatou twins while managing club affairs. Beneath her polished exterior lies a tension between vulnerability and authority. She enforces respect through strict etiquette, chastising Midari’s informal speech or others’ perceived vulgarity. Though manipulative, she shields club members from exploitation and negotiates to safeguard cultural heritage, revealing a guarded yet principled core.