Alice Cartelet is a petite teenager with a short frame frequently mistaken for an elementary student. She has lightly curled blonde hair typically worn in pigtails, one secured by a childhood hair ornament gifted by Shinobu Omiya, and bright blue eyes. Standing at 139 cm tall, she has grown only three centimeters since elementary school, contributing to a noted height complex. Her school attire consists of the standard uniform paired with white stockings, a pink cardigan, and black Mary Janes, switching to shorter socks during summer. Casual outfits often feature feminine dresses that emphasize her youthful appearance.

Personality-wise, Alice is generally quiet and shy, particularly around adults or unfamiliar situations, and exhibits fear toward some dogs. Despite her intelligence, she displays childish pettiness when upset or envious. She shows compassion and kindness to friends but offers bluntly honest opinions, occasionally attempting to phrase negative comments positively. A deep passion for Japanese culture drives much of her behavior, stemming from her initial homestay experience with Shinobu in England. She maintains intense dependence on Shinobu and displays jealousy when others interact closely with her, often intervening or changing the subject. Her voice possesses a noted soothing quality, especially when singing.

Her background traces back to England, where she first met Shinobu during a week-long homestay. Initially unable to communicate due to language barriers, they became close friends within a week, sparking Alice's fascination with Japanese culture. This connection led her to transfer to Shinobu's high school in Japan years later. The familial link deepened with the revelation that Shinobu's mother studied in England decades earlier, befriending Alice's mother and indirectly facilitating Shinobu's homestay with the Cartelet family.

Key relationships define her character. Her central bond with Shinobu is marked by clinginess and protectiveness; she dislikes others gaining Shinobu's attention and frequently bickers over cultural differences like hair dye preferences. She admires Shinobu's older sister Isami but resents her teasing and closeness to Shinobu, even offering an expensive ring to "claim" Shinobu. With Yōko Inokuma, she engages in mutual teasing and delivers blunt critiques of Yōko's academic struggles. Her childhood friendship with Karen Kujō mixes affection with resentment when Karen interacts closely with Shinobu. She shares an academic kinship with Aya Komichi, bonding over shared intelligence and reserved personalities.

Character development unfolds across the series and film. Initially possessive of Shinobu, Alice gradually matures to accept shared friendships. In "Thank You!!", during the senior trip to Kyoto and Nara, she impresses others with her cultural knowledge, showcasing her deepened connection to Japan. Nearing graduation, she struggles to express her plans to return to England for university, fearing separation from Shinobu. This culminates in Shinobu deciding to pursue studies in England alongside her, fulfilling their mutual desire to stay together. Emotional growth is highlighted when she openly cries during graduation, contrasting her earlier reserved demeanor. Her journey concludes with settling into university life in England alongside Shinobu, later hosting visits from Karen, Aya, and Yōko.