Mireille Grangeon is a former noblewoman who once served as a strategist for the governor of Missian. After leaving that position, she traveled the world, living a carefree life funded by her savings. She was discovered by a group of mercenaries known as the Shadows and later recruited by Ars Louvent to become the fourth retainer of House Louvent. Mireille presents herself with an easygoing, relaxed demeanor, often seen drinking or sleeping. However, beneath this casual exterior lies a sharp intellect and exceptional tactical skill. She is a well-established tactician and diplomat, equally capable in combat. Her initial introduction to Ars's household is marked by a controversial reputation, but Ars recognizes her potential and hires her. Mireille is also the older sister of Thomas Grangeon, who serves as an adviser to Vasmarque, one of the sons of the Duke of Missian. Physically, she has very long brown hair and purple eyes, and she often wears a cape and thigh-high boots. Her role in the story is that of a key strategist for Ars, helping him navigate political and military challenges. Through her service, she demonstrates loyalty and a pragmatic approach, gradually earning the trust of those around her. Her development involves overcoming initial skepticism and proving that her abilities are genuine. Notable abilities include diplomacy, strategic planning, and combat prowess.