Aoi Yumemiya is a first-year student at Onegai Middle School and one of the main characters in the series. She is depicted as a remarkably talented individual, excelling in both academic studies and athletic pursuits, which has earned her the admiration of her peers. Her personality is defined by a strong sense of responsibility and a caring nature, and she is characterized by her unwavering determination, as she never gives up on her dreams.

In the story, Aoi is an established and popular performer known as an AiPri, an idol princess. She lives with her mysterious, plush-like companion named Fortu, who is a creature known as a Puri-usa Friend. Aoi is actively searching for another AiPri who can grant a wish for Fortu, a quest that leads her to the protagonist, Konomi Inori, at the beginning of the series. Together, Aoi and Inori form a unit called the Onegai Kanae-tai, which translates to the Wish-Granting Unit, where they use their live performances to fulfill the wishes of the townspeople. A key aspect of her role involves handing a special item called a Mirror Pact to Inori, which allows Inori to make her own AiPri debut. Through their shared activities, Aoi forms a close partnership with Inori, believing that destiny brought them together. Her notable abilities include her proficiency in her performances as an AiPri and her general excellence in school and sports.