Carol Olston, a British-Japanese high school student, stands out with her wavy blonde hair, green eyes, petite frame, and curvaceous figure, often accentuated by pink hair accessories and a casually modified uniform. Her inverted nipples are occasionally depicted, while her bubbly demeanor earns her the nickname "cotton candy."

Beneath her airheaded cheerfulness lies sharp intelligence, showcased by her top academic rankings and knack for blunt, socially unaware remarks. She navigates friendships with playful chaos, gifting gold bars or teasing peers like Tomo Aizawa about crushes, yet displays surprising emotional insight, subtly advancing Tomo’s romantic pursuits.

Born to Eddie and Ferris Olston—her mother having given birth at 13—Carol’s wealthy British upbringing fuels cultural quirks, like assuming all homes mirror her eccentric family. A childhood encounter with Kousuke Misaki, whom she defended from bullies before distractedly chasing a butterfly, forged their bond. Kousuke’s protective loyalty gradually intertwines with Carol’s direct romantic gestures, evolving their playful "engagement" games into genuine affection.

Her friendships pivot on comedic contrasts: Misuzu Gundou’s sarcasm bounces off Carol’s oblivious persistence, creating a trio that balances Tomo’s brute strength and Misuzu’s cunning with Carol’s charm and academic flair. Family visits highlight her mother’s similar whimsy, reinforcing Carol’s unconventional roots.

Fluent in English and Japanese, Carol’s trivia-rich background includes a surname nod to Holstein cattle—a playful wink at her figure—and harmless fabrications about her bra size. Despite occasional white lies, her loyalty in friendships and romance remains unwavering, blending innocence with cleverness in every chaotic, golden-hearted scheme.