Marguerite Farom is the third princess of the Farom Kingdom and was originally the fiancée of the late hero Sion. At sixteen years old, she has a calm and elegant demeanor, with long, jet-black hair and a distinctive beauty mark beneath her right eye. Her upbringing was extraordinarily strict: because the king decreed she would marry the hero, she was subjected to rigorous education in academics, arts, etiquette, and combat from early childhood. This grueling training left her with a chronic condition that forces her to constantly eat in order to sustain her magical energy.

Despite her sheltered and pressured past, Marguerite is kind-hearted, well-mannered, and treats nearly everyone with politeness. Her gentle nature grows stronger as the story progresses, and she shows increasing resolve when protecting those she cares about. Her primary motivation after Sion's death shifts from fulfilling her duty as a fiancée to supporting the new hero, Touka Scott, whom she eventually falls in love with after he risks his life to shield her. She dreams of marrying Touka once their quest to save the world is complete.

In the story, Marguerite joins Touka's party as a vital ally. She is a powerful mage with extensive knowledge of magic and combat, trained from youth by her strict tutor Isaac Gardner. Her abilities include high-level spellcasting, and her condition requires her to consume food regularly to replenish her mana, a quirk that becomes both a limitation and a distinctive trait. Throughout the journey, she develops from a princess bound by royal expectations into a determined fighter who actively contributes to the mission and grows emotionally closer to her companions. Her key relationships include her former tutor Isaac, the late hero Sion, and her deepening bond with Touka, as well as friendships with other party members such as Anri and Yuna.