Aoi is an elf with short, pale green hair styled with bangs covering her right eye and vivid green eyes. In the world of Astrum, she wears a green beret fastened with brown elastic and a white or blue feather. As a Transfer Student at St. Theresa's Academy, she dons a dark purple-blue beret accented by a green or white feather, while her real-life counterpart has dark green hair that obscures both eyes and no headwear. Profoundly shy and struggling with social anxiety, especially when it comes to initiating friendships, Aoi possesses a determined resolve to conquer her personal challenges and battle against loneliness. She founds the Byebye Loneliness Brigade (BB-dan), a self-created group dedicated to tackling isolation, and appoints Yuuki as captain under the persistent misconception that he shares her deep experience of friendlessness. This misunderstanding becomes a recurring theme in their dynamic, even as Yuuki’s many connections inadvertently reinforce her perception of shared loneliness. In Astrum, Aoi belongs to the Forestier guild and becomes a temporary transfer student at St. Theresa Girls’ Academy through Misato’s arrangement. She practices introductions and tackles social challenges, such as securing the school’s Limited Bread to foster bonds, culminating in successfully inviting a fellow shy student to join her group. Her confidence grows through the Friendship Club alongside peers Chieru Kazama, Chloe, and Yuni Shingyouji, an arc that unfolds in the story event Coward of the Forest and the Heretic of the School. Her real-life counterpart mirrors this growth: while watering school flowers, she encounters another girl tending to the same task and, despite initial nervousness, musters the courage to speak, resulting in a new friendship. In combat, Aoi serves as a Physical Attacker and Debuffer. Her primary strength lies in applying poison-based damage over time that ignores enemy defense. Her skills include Poison Arrow+, which targets the frontmost enemy and applies Poison or upgrades it to Toxic if already active, and her Union Burst, Venom Blooming, which deals area physical damage and inflicts Poison or Toxic with enhanced effects against poisoned targets. This poison-focused approach allows her to effectively counter high-defense opponents. Her dialogue consistently emphasizes self-improvement and supporting others, as reflected in quotes such as, Even if I only have a little power... I still want to support everyone, and Each time the BB Team meets... I've started wishing that tomorrow could come a little bit quicker.