Chika Fujiwara is a student at the prestigious Shuchiin Academy and serves as the secretary of its student council. She is a fair-skinned girl with shoulder-length light pink hair, blue eyes, and a distinctive black bow securing her bangs. Born on March 3, she stands at 154 cm tall. Chika comes from an exceptionally prestigious political family; her great-grandfather was once the Prime Minister of Japan, her uncle is a current cabinet minister, and her mother is a diplomat. As the middle child of three sisters, with an older sister named Toyomi and a younger sister named Moeha, she grew up in a loving but overprotective household where common forms of entertainment like video games were forbidden.

In personality, Chika is a bubbly, energetic, and cheerful individual who almost always has a smile on her face. She is kind-hearted and always looking to have fun, frequently initiating strange activities and games with her fellow council members. Her defining trait is a lack of awareness of the romantic tension between student council president Miyuki Shirogane and vice president Kaguya Shinomiya. She remains completely oblivious to their elaborate psychological battles to force the other to confess love, and her innocent, chaotic actions often inadvertently disrupt their schemes. While this obliviousness leads others to see her as simple-minded, Chika is surprisingly perceptive about the feelings of other students, such as Yu Ishigami and Miko Iino, and has a deep obsession with romance, proclaiming herself a "love detective" who freely gives relationship advice despite having no romantic experience herself.

The primary role Chika plays in the story is as a wildcard and comic foil. Her unpredictable nature serves to throw the main love story off-balance in humorous ways, ensuring that the "war" between Shirogane and Kaguya can continue without a premature resolution. Beyond being a disruptor, she acts as a good friend and a source of warmth and sanity within the often-tense student council room. Her relationships with other characters are distinct. She has been a close friend of Kaguya since middle school, and despite Kaguya's reserved nature, the two share a deep bond and often have sleepovers. With Miyuki, she frequently takes on the role of a reluctant but dependable tutor, helping him train in areas he lacks, such as volleyball, singing, and dancing, though she often swears never to teach him again after each exhausting session. She bickers constantly with Yu Ishigami, who often calls out her mistakes, and she delights in teasing the younger and more serious Miko Iino, seeing her as a fun new source of entertainment.

Despite her ditzy exterior, Chika possesses a range of notable abilities. She is an accomplished pianist who has won gold prizes in national competitions and is a polyglot, fluently speaking five different languages including Japanese, English, and French. She is a member of the Tabletop Game Club and loves German-style board games, puzzles, and ramen, the latter of which she consumes with the expertise of a professional connoisseur. Ironically, while she hates lying, when playing competitive games like poker, she reveals a devious side and bluffs masterfully, though she often gets caught cheating. The character was conceived by creator Aka Akasaka to serve as a lighthearted element with no hidden darkness or internal monologue to contrast the scheming protagonists, with Akasaka stating that he drew her to be everyone's heroine. Throughout the series, while she remains mostly static as an agent of chaos, her hidden depths as a talented and emotionally intelligent young woman from an influential family become increasingly clear.