Kurumi Haibara is a central figure, characterized by her energetic and multifaceted personality, blending girlish and tomboyish traits with high spirits and a lively demeanor. She possesses striking red hair styled with spiky bangs and lengthy twin tails extending past her hips, blue tareme-shaped eyes, a slim teenage frame standing 163 cm tall, and pale skin. Her physical measurements are 91-58-86 cm (bust-waist-hip).

Her background centers on a personal quest driven by her father's disappearance. Motivated to uncover his whereabouts, she actively investigates while frequently carrying a camera, reflecting her interest in photography; this pursuit significantly shapes her actions and development.

Personality-wise, Kurumi is talkative yet sharp-tongued, occasionally short-tempered, and engages readily in teasing others while also being subject to teasing herself, showcasing her mischievous and socially interactive nature. Despite a humorous exterior, she demonstrates insightfulness, particularly during investigations.

Within her social environment, she navigates school life as a classmate and student club member. Her relationships include being a daughter, though specific familial dynamics beyond her father's absence remain unelaborated; her interactions often involve collaborative group activities.

Her character design features varied attire, including school uniforms with neckties, miniskirts, thigh-high stockings, glasses, bikinis, and shirts across different contexts.