Mayaka Ibara is a main character in Hyouka. She is a student at Kamiyama High School, where she belongs to class 2-C. She serves as a volunteer librarian and is a member of the Classic Literature Club as well as the Manga Society, though she eventually leaves the Manga Society due to conflicts with its members. She is short in stature, with brown hair that reaches just past her ears and pinkish-purple eyes. She has known Houtarou Oreki since elementary school, having been in the same class as him for nine years, which creates a long-standing and often friction-filled dynamic between them.

Mayaka has a personality defined by strictness, bluntness, and a strong sense of responsibility. She holds herself and others to high standards and does not hesitate to point out mistakes directly. This directness can come across as harsh or irritable, but it stems from a place of fairness and a desire for things to be done correctly. She is known for giving her friends nicknames, such as calling Satoshi Fukube Fuku-chan and Chitanda Eru Chi-chan. Her primary motivation for joining the Classic Literature Club is her long-held romantic interest in Satoshi Fukube, whom she met in middle school. She has pursued him persistently and eventually begins dating him.

Within the story, Mayaka serves as the most emotionally expressive and morally straightforward member of the group. She provides a contrast to Houtarou energy-conserving indifference and Satoshi lighthearted evasiveness. Her participation in the club allows her to contribute a practical and critical perspective, and she often acts as the one who calls out logical or ethical inconsistencies. Her role as an aspiring manga artist is also significant. She admires a student-made manga called A Corpse by Evening and works on her own manga, which reflects her personal ambition and creative drive. Her involvement in the Manga Society becomes a source of tension, and her decision to leave it marks a key point in her personal development, as she learns to prioritize healthier relationships over stubborn persistence.

Mayaka key relationships include her friendship with Chitanda Eru, which is warm and supportive, and her complicated bond with Houtarou Oreki, whom she often criticizes but also respects. Her relationship with Satoshi Fukube is central to her character arc. She is the one who pursues him romantically, and he often deflects her advances in a playful manner. Over the course of the series, she shows growth in learning to navigate the complexities of friendship and collaboration, becoming more aware of social nuances without losing her core honesty and directness. Her notable abilities include her talent for drawing manga and her extensive knowledge of literature, which she applies to the club investigations.