Marie is one of the twelve sisters in the anime Sister Princess: Re Pure, distinguished by her frail health and gentle demeanor. She has a weak constitution and has spent a significant amount of time in the hospital due to her illness, a background that shapes much of her character. While confined indoors, she developed a deep love for reading, particularly romance and adventure novels, which allowed her to travel the world through her imagination. This love of literature is a central aspect of her personality, as she appreciates the escapism that stories offer and often dreams of visiting the natural settings she reads about, such as the ocean, the forest, and the beach at sunset. Her motivations are closely tied to her desire to experience the world beyond her sickbed, and her greatest wish is to walk along a beach with her older brother, Wataru, during a beautiful sunset. In the story, Marie serves as a gentle and emotionally sensitive presence among the sisters, and her role often highlights themes of yearning, recovery, and the strength found in familial bonds. Her most important relationship is with Wataru, whose presence gives her the strength and happiness she needs to face her challenges. She also shares a profound bond with her pet Golden Retriever, Michael, who acts as her constant guardian and friend whenever her brother is not around. Michael never leaves her side during her illnesses and even alerts others when she needs help. Over the course of the series, Marie shows development as her time with her brother helps her grow stronger and more confident, allowing her to move beyond the limitations of her condition. Notable abilities include her extensive knowledge gained from reading, her emotional sensitivity to nature and literature, and the unwavering loyalty of Michael. She is characterized by her gentle, bookish nature and her deep appreciation for the warmth of natural settings and the love of her family.