Brigadier General Sarah Jones, a British soldier, embarks on an initial mission to locate and rescue two squadmates—Charlie and Sam Son—subjects of the military experiment "Human Weaponization Concept" codenamed Rabbit, identifiable by their red eyes when enraged. After Charlie dies during an early confrontation aboard a cruise ship, her objectives shift to rescuing Sam Son and avenging Charlie’s death. She allies with Taito Masaki, Gerard Gelain, and Kicks Rockwell, joining their journey to Grazia and their assault on the Spiral Palace commanded by Captain Klaus Daggats.

Inside the Spiral Palace, she confronts Suzaku Kimonin, a Japanese monk serving Klaus who seeks battles against formidable opponents; this duel is one of the featured individual confrontations during the tower assault. Her storyline converges with Klaus Daggats’ role in the Rabbit project and the abduction of her soldiers, cementing him as her personal antagonist due to his responsibility for the events impacting her unit. Her military background and unwavering commitment to her squadmates persistently drive her actions throughout the conflict against Klaus Daggats and the Spiral Palace forces.