Celia first met Rio in the slums, later encountering him again at the Royal Academy when she discovered him asleep in the library surrounded by books and notes. Impressed by his determination and rapid progress in self-study, she offered to tutor him during her spare time. Through these lessons, she recognized his extraordinary ability to learn and grew close to him. Over time, Rio frequently visited her laboratory, where they shared tea together, and he often helped her tidy the room, unable to tolerate the mess.

Following the academy examinations, Celia defended Rio against accusations of cheating made by noble students who were envious of his remarkable performance. Angered by the repeated bullying he endured despite his talent and effort, she openly supported him.

When Rio was later accused of involvement in a cliff incident, Celia suspected a mistake. Her suspicions were confirmed when Rio secretly entered her room to bid her farewell before fleeing the country. Realizing his innocence, Celia was devastated by his departure. Although Rio promised to send her a letter, his absence left her heartbroken, and she reportedly cried for days after his escape.

Celia Claire is depicted as a young teenage girl with a petite frame and a youthful appearance. She has long silver hair, which she usually styles in twin ponytails while allowing the rest to fall freely down her back. Her distinct hair color and refined features highlight her noble background as well as her status as a prodigious magician.

When adopting her disguise as “Cecilia,” Celia alters her appearance through magic. In this form, she ties her hair into a single side ponytail and uses transformation magic to change its color to blonde, effectively concealing her identity. This alternate appearance allows her to move more freely without drawing the attention associated with her reputation as a genius magician.

Celia Claire is portrayed as a kind and refined young noblewoman who treats others with respect regardless of social status. Unlike many of her peers, she does not look down on those beneath her rank and often shows genuine kindness and patience in her interactions. She is particularly fond of tea and demonstrates a refined taste, being somewhat particular about how it is prepared and enjoyed.

At the same time, Celia exhibits traits of absentmindedness when immersed in her research. When her curiosity is sparked, she tends to isolate herself in her laboratory for extended periods, often neglecting her surroundings. As a result, her room is frequently cluttered, reflecting her lack of skill in housework and practical chores. She is also somewhat introverted and physically weak, struggling with tasks that require stamina or endurance. Despite these shortcomings, her intellectual brilliance and warm demeanor make her highly respected and beloved by those around her.

Magic
Celia Claire is recognized as the most talented magician of the Strahl Region in the modern era. Gifted with extraordinary magical capacity—measured at nearly twenty times greater than that of a standard royal magician—she is capable of performing a wide range of elemental spells as well as developing original magical devices. Many of her inventions have achieved renown across the region, though one such device broke unexpectedly when exposed to Rio’s power.

Hyper Physical Magic
A form of body-strengthening magic that enhances physical ability. While Celia can perform it, prolonged use overwhelms her, as her mind cannot fully withstand the strain of her own heightened movements.

Elemental Magic
Celia has demonstrated proficiency in multiple elemental schools of magic, including:

• Earth Magic: manipulation of terrain and soil.
• Water Magic: control of water and moisture.
• Wind Magic: generation and direction of air currents.
• Ice Magic: freezing and shaping water into ice.
• Lightning Magic: channeling and releasing electrical energy.

Rio / Haruto Amakawa
Rio is Celia’s childhood friend and eventual love interest. She first met him in the slums while searching for the kidnapped Princess Flora, where, unlike other nobles, she treated him with dignity and respect. After Rio was tortured by Charles Arbor, Celia healed his injuries, marking the beginning of their close bond. She later helped him adapt to life at the Royal Academy, teaching him literacy, tutoring him in academics, and defending him against the bullying and suspicion of other nobles. Rio eventually became her personal assistant in her magical research, further strengthening their relationship.

When Rio was falsely accused of attempted murder during a training exercise, Celia refused to believe the charges and continued to trust him. His sudden departure from the academy devastated her, and she wept for days after his escape. Over time, it becomes clear that Celia harbors romantic feelings for Rio, which she fully acknowledges by Volume 5 of the light novel when faced with her arranged marriage. She also displays signs of jealousy when Rio interacts with other women, particularly Aishia.

Christina Beltrum
As a loyalist to the Beltrum royal family, Celia shows deference and respect toward Princess Christina Beltrum, bowing to her as a member of the royal household. Their relationship is also professional, as Celia once served as Christina’s tutor. The two share mutual respect, with Christina recognizing Celia’s exceptional talent as a magician.

Flora Beltrum
Celia also maintains a respectful relationship with Princess Flora Beltrum, whom she has supported and instructed. Like with Christina, Celia’s role as a tutor establishes a bond of mutual trust and regard.

Roanna Fontaine
Celia respects Roanna Fontaine as both a former student and a fellow noblewoman. Their connection is professional but cordial, reflecting Celia’s role as a teacher.

Ayase Miharu
Celia and Ayase Miharu get along well, especially in the web novel, where they live together with the Sendou siblings. Celia teaches Miharu and her companions the Strahl language, while Miharu teaches Celia cooking particularly in ways suited to Rio’s tastes showcasing the reciprocity in their friendship.