Claudine Saijō is a second-year student in the Actor Training Department of Seisho Music Academy's 99th Graduating Class, holding the second rank in her class. Born to a Japanese father and French mother, she began as a child actress, appearing in television commercials like "Chantry Ma'am" (2007) and "Makenain A Ointment" (2008), plus stage productions including "Arrie" (2011) and "Mary Hopkins" (2012). This early exposure fostered a belief in her unique talent among peers, a perception challenged upon meeting Maya Tendo during Seisho auditions. She attended Minato Women's International Private Junior High School, training extensively in classical ballet, modern dance, jazz dance (since 2006), vocal music (since 2007), cello (since 2008), tap dance (since 2010), social dance (since 2012), and locking dance (since 2015), forming the foundation of her technical skill. Claudine has ash-blonde waist-length hair, magenta eyes, and typically wears a black headband. Her Seisho uniform consists of a gray blazer with dark-gray trimming, a gray knife-pleated skirt, a white button-up shirt, a red ribbon tie, brown loafers, and black thigh-high socks. Casually, she favors a light-blue puff-sleeved blouse with a deep V-neck, black cuffed capri pants, and red shoes. For rehearsals, she wears a pink leotard with gold trims and grey leggings. Her revue outfit features a black jacket with silver piping and epaulettes, a white button-up shirt, a golden belt, a black kick-pleated skirt with a tulle tail, black boots with golden details, and a red pelisse jacket. Her weapon is a longsword bearing a black gem at its base. Confident and straightforward, Claudine values determination, often stating unwavering will is essential to achieve desires. She exhibits emotional intelligence, noticing subtleties like Yachiyo's covert observations during "Detective Karen on the Case." Friendly with classmates, she uses first names and engages in light teasing, but becomes intensely competitive when challenged, particularly by Maya. Their rivalry began with Claudine's frustration at consistently placing second, evolving into mutual respect after collaborative performances like the Revue of Duet, where Claudine supported Maya's brilliance. Her relationship with Maya is central. Though rivals, they are frequently paired in classes and private practice, as Maya views Claudine as her only equal. After losing to Karen and Hikari in revue auditions, Claudine broke down, blaming herself for failing Maya, but Maya reassured her in French, solidifying their bond. Post-audition, their interactions shifted from aggressive competition to a quieter, supportive partnership. Claudine shares a close friendship with Futaba Isurugi, who provides comic relief and emotional support, staying in Claudine's room during a conflict with Kaoruko Hanayagi. Later, during "Rondo Rondo Rondo," Claudine focused on mentoring classmates: addressing Mahiru Tsuyuzaki's audition insecurities, encouraging Junna Hoshimi to aim higher, and advising Futaba Isurugi to audition for the New National troupe. She channeled her competitive drive into creative endeavors, overseeing the script, costumes, and stage effects for "Dazzling Vampire," reimagining the vampire narrative with a modern setting and humor. Professionally, Claudine was scouted by Théâtre du Flamme in France, a prestigious troupe rivaling Maya's choice of New National Theater, signifying her independence and ambition beyond their rivalry.