The protagonist and central figure of the film, a dedicated physician stationed on a Seto Inland Sea island during World War II. He leads the fight against a severe hepatitis epidemic, frequently clashing with the military authorities over his medical practices and diagnoses. Locals affectionately nickname him 'Dr. Liver' (Kanzō-sensei), a term that highlights his persistent focus on liver ailments and adds a layer of humorous irony to his serious humanitarian efforts amidst the backdrop of Japan's wartime decline.