Cecilia Alcott, a first-year student at the IS Academy and England's IS Representative Candidate, hails from British aristocracy. Her parents perished in a train accident, later exposed as an assassination tied to their treasonous acquisition of an IS core. This tragedy left Cecilia the sole heir to the Alcott fortune, forcing her to defend it against claimants. Witnessing her father's perceived weakness within the family fueled her determination to marry someone strong, a goal complicated by societal shifts after IS technology emerged. Initially projecting arrogance and nationalism, Cecilia believes England superior and challenges Ichika Orimura to an early duel. This confident facade conceals vulnerabilities from her troubled past and the burden of safeguarding her inheritance. After a duel victory secured only by a technicality, Cecilia develops romantic feelings for Ichika. She frequently fantasizes about intimacy and displays possessive, "yandere" tendencies, nearly shooting Ichika when he almost kisses another girl and joining others in a sniper attempt after witnessing Laura kiss him. As the pilot of the Blue Tears IS, Cecilia specializes in long-range sniping and shooting, leveraging military training to achieve A-Rank status. Her unit employs optical drones and versatile weaponry, though overconfidence sometimes hinders her effectiveness. She acknowledges being the weakest among peers in direct comparisons and lacks group formation experience due to Blue Tears' independent combat role. She later learns to bend laser beams for tactical advantage and demonstrates fencing proficiency, holding her own against her maid, Chelsea, by removing clothing for better mobility. Beyond combat, Cecilia plays violin and piano, excels at tennis—winning an academy tournament—and gradually improves her initially terrible cooking by following recipes, though she occasionally experiments. Her development includes moments of vulnerability, like seeking Ichika's support during personal struggles, and participation in group activities, such as joining other girls at Ichika's house during summer vacation to cook and play games. Cecilia possesses light blue eyes, long blonde hair with drill-like curls, and a slender, curvaceous figure. She wears a modified IS Academy uniform featuring a longer skirt, black frills, and dark tights, reflecting her noble status. Her standby IS manifests as ear accessories. In casual settings, she favors high-class dresses. Her romantic inclinations lead her to consider bold or erotic clothing, like lingerie during a massage session with Ichika, though she refrains from acting on these thoughts.