Ai Minamizato is a 16-year-old high school student with a birthday on December 1. She has brown hair, red eyes, stands 1.53 meters tall, and has physical measurements of 80-59-85. Her blood type is O.

She possesses a shy disposition that becomes pronounced around male individuals, often making it difficult for her to speak to them without considerable effort and encouragement. In these social situations, her knees may tremble, and she typically relies on support from her friend, Miyuki Iijima, who provides encouragement and sometimes intervenes directly. Her general inexperience in interactions with the opposite sex is a recurring aspect of her character.

In the original OVA production, she is an underclassmate at the same school as the central characters and develops romantic feelings for an upperclassman named Tohru Nagase. Her affection for Tohru introduces an external complication in the primary romantic dynamic between Tohru, Mizuho Yuuki, and Miko Kamiyama.

In the television series adaptation, her role is similar but directed toward a different character. Here, she has secretly held romantic feelings for a fellow student named Tsuyoshi for a considerable time. She is introduced in a scenario where she is attempting to rescue a kitten stranded in a tree, an act through which she first comes to Tsuyoshi's attention.