Tatsuko Gakumazawa is a classmate and close friend of Illyasviel von Einzbern, Suzuka Kurihara, Nanaki Moriyama, and Mimi Katsura, later forming bonds with Miyu Edelfelt and Chloe von Einzbern. Her family runs a martial arts dojo, though she juggles part-time work at a beachside venue and festival events. Despite this upbringing, her physical coordination falters, marking her as the least athletic in her group. Dodgeball and similar activities highlight her clumsiness, with frequent comedic mishaps underscoring her reputation as the group’s underdog. Playfully immature, Tatsuko thrives on chaotic antics that spiral into slapstick disasters, unwittingly dragging others into absurd predicaments. Her wide-eyed admiration for her father and brothers—skilled martial artists—contrasts sharply with her own ineptitude, amplifying the humor of their dynamic. A recurring quirk defies logic: Tatsuko routinely survives high-risk escapades with nothing but superficial scrapes. These near-miraculous escapes become a signature gag, framing her as an accidental survivor in a world where gravity and consequence seem to bend around her.