Miko Uno is a secondary character in the anime Fantasista Doll. She is the younger sister of the main protagonist, Uzume Uno, and is in her third year of elementary school. Physically, Miko has medium-length blonde or light orange hair that reaches her shoulders, often styled with hair bobbles, and yellow or brown eyes. Her typical attire includes a dress with a neckerchief, slippers, and a bag.

Her personality stands in contrast to her older sister's carefree and sometimes impulsive nature. Miko carries herself with a calm, dependable presence that belies her young age. She possesses a sense of maturity that makes her seem more levelheaded and practical than Uzume, often acting as a steadying influence in their household. At the same time, she retains a warm and unmistakably childlike sincerity, balancing early maturity with genuine gentleness. She naturally takes on the role of a gentle caretaker, looking after those around her with quiet compassion.

Miko's primary motivation is to support her sister and maintain a sense of normalcy at home. She is not directly involved in the battles involving the Fantasista Dolls; rather, her role is to provide emotional grounding and familial support for Uzume. She represents the ordinary, everyday life that Uzume strives to protect. Her key relationship is with Uzume, whom she cares for deeply and often helps keep grounded. Miko also interacts warmly with the dolls when they appear in civilian settings, showing no fear or resentment towards them.

In terms of development, Miko remains a consistent presence throughout the series, offering a stable home environment and unconditional support for her sister as Uzume navigates her new responsibilities as a Doll Master. She does not have any supernatural abilities or combat roles, but her notable ability lies in her emotional intelligence and her knack for caring for others, which quietly reinforces the series' themes of friendship and family.