Nanaki Moriyama shares a classroom and friendship with Illyasviel von Einzbern, Suzuka, Tatsuko, Mimi, Miyu Edelfelt, and Chloe von Einzbern at Homurahara Academy's elementary division in Fuyuki City. Her background prior to these friendships remains largely undocumented. She typically displays a relaxed, caring, and often laid-back or lazy attitude. However, a notable temper flares quickly when she encounters displeasing situations, especially those involving her older sister, a protective reaction grounded in her deep respect and care. She readily forgives if conflicts resolve or apologies are offered. Regarding her capabilities, Nanaki possesses the standard physical attributes of an elementary school student but shows hints of significant dormant power. She attributes this to a family lineage blessed with generations of untapped physical prowess. This potential manifests when she rapidly masters the Gakumazawa Style martial art and effortlessly defeats the adult instructor who taught her. Observers, including Illya, recognize this innate combat aptitude, describing her as a natural genius in learning martial skills despite her age.