Ariko Kasumi is a supporting character in the anime Märchen Mädchen. She is a fifteen-year-old girl who stands 146 centimeters tall, with a birthday on June 28th. She has purple hair cut to shoulder length and blue eyes, though her youthful appearance often leads others to mistake her for an elementary school student, a comparison that she deeply resents.

Her background is closely tied to the Tsuchimikado family, as the Kasumi family has historically served them in a master-servant relationship. This connection makes her the childhood friend of Shizuka Tsuchimikado, to whom she is fiercely loyal. This loyalty forms the core of her personality and drives many of her actions. She has a sharp sense of humor, often enjoying dark jokes, and her hobbies include napping, a skill she can perform anywhere.

Within the story, Ariko is a Mage contracted to the magical original fairy tale of Issun Boshi. Her role is that of a protective figure, particularly regarding Shizuka. This protective nature can manifest as hostility towards those she perceives as threats; for instance, she once threatened a fellow student with severe punishment simply for following Shizuka to the magic academy. Despite her sometimes aggressive tendencies, she is capable of forming other bonds, as suggested by moments of casual intimacy with classmates, such as sharing an indirect kiss.

In terms of abilities, Ariko's power is derived from her contract with the Issun Boshi fairy tale, though specific details of her magical capabilities are part of her identity as a mage. Her personality is defined by a mix of loyalty, a short temper regarding her stature, and a preference for rest, making her a complex character driven by historical duty and personal friendship.