Fumika is a ghost dwelling at Mahora Academy, consistently portrayed with long, straight black hair, pale skin, and dark eyes, often clad in a distinctive white dress. Her tragic origin stems from perishing in a fire that destroyed the old academy library decades before the main timeline; this event anchors her and several other student spirits to the academy grounds as spectral residents, with the library's loss forming her core sorrow.

Personality-wise, Fumika exhibits a gentle, soft-spoken, and inherently shy demeanor, carrying a persistent melancholy tied to her ghostly existence. Despite her timidity, she demonstrates kindness and an ability to forge meaningful bonds. She interacts with living students, particularly forming friendships with individuals like Yue Ayase and Nodoka Miyazaki. These relationships encourage her gradual emergence from withdrawal, evidenced by participation in events such as the Mahora Festival alongside living peers, showcasing subtle development in overcoming shyness.

Her character arc revolves around her ghostly nature, exploring unresolved tragedy, connection beyond death, and finding moments of peace within spectral limitations. Her narrative centers on adapting to an unchanging state while engaging with a changing world.