Diana Spencer's anime portrayal spans her early childhood to early teen years. She exhibits a shy, apologetic nature, often biting her thumb when anxious. Born into an aristocratic family, her father initially expresses disappointment at her birth due to desiring a male heir, though he later accepts her into the Spencer lineage. Following her parents' divorce, she relocates to London to attend Riddlesworth Hall boarding school, where she navigates new friendships and familial challenges while striving to embody the ideals of a "Proper Lady." Her experiences include bonding with peers and participating in school activities, such as a pet contest featuring her guinea pig, Peanuts. Diana displays a strong affinity for animals, reacting with visible delight to bunnies and woodland creatures, and is characterized as a friend to all living things.

Her personality reveals introspection and emotional vulnerability, frequently praying for family reconciliation and displaying sadness over her parents' separation. Rainbows serve as a key symbolic motif, culminating in a scene where she runs toward one while declaring her resolve to stop crying and seek her grandmother's guidance. The narrative hints at her future through a nascent romantic interest in Prince Charles, framed by her aristocratic upbringing and societal expectations.

The anime emphasizes Diana's emotional growth, particularly in adapting to boarding school life after her family's upheaval. A seventh-birthday surprise party organized by her peers marks a turning point, reinforcing themes of community and resilience. Throughout, she maintains distinctive traits like her love for cream puffs and a signature blue sweater, aligning with her earnest, kind-hearted navigation of childhood challenges.