Chika Fujiwara holds the position of secretary for Shuchi'in Academy's student council. She hails from a politically prestigious family: her great-grandfather served as Japan's Prime Minister, her uncle as the Minister of the Right, and her mother works as a diplomat. Chika has an older sister, Toyomi, and a younger sister, Moeha. Her upbringing, while loving, imposed restrictions, forbidding recreational activities like video games. This led her to cultivate unconventional hobbies, including German analog games and puzzles.

A childhood piano prodigy, Chika won first prize in the PTNA National Piano competition during fourth grade. Intensive practice consumed her playtime until Kaguya Shinomiya advised her to quit if she disliked it. After quitting, Chika challenged Kaguya to a game battle to become friends, initiating their close middle school friendship. Kaguya's personality often obscures this bond from others.

Chika displays a cheerful yet eccentric personality marked by swift mood shifts from innocent to temperamental. She frequently invents games for the student council, showcasing a competitive streak and willingness to cheat, though she is invariably caught. Despite a sometimes simple-minded demeanor, she possesses significant talents: fluency in five languages and unexpected perceptiveness about romantic feelings, leading her to style herself as a "love detective." Paradoxically, she remains oblivious to the mutual attraction between Kaguya and student council president Miyuki Shirogane.

Her unpredictable nature consistently disrupts elaborate schemes devised by others. Instances include unintentionally foiling an umbrella-sharing plan between Kaguya and Shirogane, inadvertently impressing Tokyo's "Four Ramen Emperors" with her unconventional eating style, and causing chaos during council games like the balloon-popping incident where she manipulated Miko Iino before accidentally popping the balloon with orange juice.

Chika reluctantly tutors Shirogane in skills like volleyball, singing, and traditional dance, developing a fear of teaching due to his initial incompetence. In one case, Shirogane taught her rap before she coached him, resulting in their rap duo performances. She owns a dog named Pes, meaning "dog" in Czech, and exhibits an ambiguous romantic orientation; while claiming to desire a boyfriend, she told Ai Hayasaka she would not mind being kissed by her, and the series' final volume indicates they live together as adults.

By the series' conclusion, Chika becomes her father's political aide while compensating for lost youthful experiences. The creator describes her as "everyone's heroine" who never falls in love but enriches the lives of those around her.