Ai Suotome, often called Ai-chan by those around her, is a five-year-old girl who joins the Futaba Kindergarten class as a supporting character. Her background sets her apart from her peers from the moment of her introduction. She is the only daughter of the immensely wealthy Suotome Zaibatsu, a fact that shapes her daily life. Born in New York, she arrives in Kasukabe not by coincidence but by a game of chance; she threw a dart at a map of Japan, and the point landed on the town, determining her destination for experiencing ordinary life. Her wealth is a constant presence, as she is almost always seen arriving and departing in a black limousine and is frequently accompanied by her dedicated bodyguard, Kuroiso.

In terms of personality, Ai presents a fascinating contradiction. On one hand, she is a refined and intelligent child, noted as being among the brightest in her class and engaged in numerous extracurricular activities such as piano, fencing, swimming, and learning foreign languages. On the other hand, she is highly manipulative and accustomed to getting her way, a skill she has clearly honed in her privileged life. She is aware of her own charm and deliberately uses it to bend others to her will. This is most evident in her interactions with the boys at the kindergarten, whom she easily captivates, turning them into her devoted admirers with little effort.

Her primary motivation, however, shifts dramatically upon meeting the series' protagonist. Having grown used to easily winning affection, she is intrigued and then completely smitten when Shinnosuke Nohara proves immune to her usual tactics, responding with his signature disinterest by declaring he has no interest in little girls. This failure to manipulate him sparks a genuine and enduring infatuation. Her primary goal becomes winning Shinnosuke's affection, and she earnestly dreams of one day becoming his wife. She uses her wealth and knowledge of his interests, such as the superhero Action Mask or the sweets Chocobi, to try and gain his attention. Her role in the story is therefore defined by this dynamic: the wealthy, cunning heiress who is constantly and comically thwarted in her romantic pursuit of the oblivious and bizarre Shinnosuke.

Her relationships with other characters are shaped by her background and her crush. She has a fierce rivalry with Nene Sakurada, which often manifests as a competitive and hostile dynamic, as both girls see each other as a threat. Masao Sato harbors a deep affection for her, but Ai rarely reciprocates his feelings, instead often treating him condescendingly or as a servant. While she can be calculating and demanding, there is a softer, more innocent side to her. Her affection for Shinnosuke is genuine, and her desire to experience a normal life shows a certain curiosity and openness beyond her sheltered upbringing.

Over the course of her appearances, Ai's character experiences a notable arc. After a period in Kasukabe, she eventually moves away permanently to Hokkaido with her family, which includes a younger brother named Kawaguchi. Despite the move, she does not disappear from the series entirely, making occasional return visits to see her friends. Her most significant development is arguably her failed attempt to conquer Shinnosuke, which paradoxically leads to her most human quality: a sincere and persistent, if often misguided, first love. Her notable abilities extend beyond academic intelligence; she possesses what could be called a "Cupid's arrow" stare that makes boys fall for her, and she is exceptionally skilled at using her charm and resources to orchestrate situations to her advantage, whether for a date with Shinnosuke or simply to enjoy a slice of cake.