Kana Fujii is a first-year high school student and apprentice healer at the Karasuma Voice Treatment Center. Her path into vocal medicine began in childhood during an asthma attack on an airplane, soothed by a healer's song—an event that irrevocably shaped her future.

She radiates cheerful energy, often uplifting her fellow apprentices. Empathetic and driven by a Helper personality type focused on others' needs, her core philosophy is: "I won't let anyone suffer on my watch."

Despite innate talent for healing song, she grapples with technical skills and theoretical knowledge during training; this contrast defines her developmental journey. Her intuitive, emotionally connected healing approach sometimes falters, as shown when assisting a pregnant woman with fellow apprentice Sonia Yanagi. Their initial focus solely on the mother triggered an imbalance by overlooking the unborn child, underscoring the vital need for comprehensive focus in vocal medicine.

Her growth involves learning to balance emotion with precision. Training under Ria Karasuma demands recognizing that incomplete focus or personal emotional interference can weaken or negate healing effects, highlighting the responsibilities and risks of their practice. Throughout her apprenticeship, she forges strong bonds with fellow trainees Hibiki Morishima and Reimi Itsushiro, facing everything from interpersonal tensions during grueling training to mutual support during evaluations.

A pivotal milestone arrives when she achieves C-rank healer certification alongside her peers, signifying their transition from apprentices to certified practitioners and validating her growth in skill and understanding of vocal medicine's complexities. Her journey embodies perseverance, teamwork, and the relentless effort required to master healing arts, culminating in professional recognition while holding fast to her core motivation: alleviating suffering through her gift.