Ai is from an extremely rich family and happened to be enrolled in to the kindergarten at Kasukabe because she threw a dart at the map of Japan and hit Kasukabe, thereby determining where she would go next. She is always seen riding in a black limousine and with a bodyguard. Many boys fell in love with her except Shin-chan. Instead, she fell in love with Shin-chan. Masao-kun likes her very much, but Ai-chan almost never pays attention to him.