Eri Nitta is a female middle school student with black hair, grey eyes, and typically wears pigtails. She begins as a reserved third-year junior high school student. During history class, her teacher Kibayashi-sensei summons the spirit of Oda Nobunaga and transfers it into Eri to cure her extreme timidity. This spiritual possession triggers a violent, permanent transformation. Eri's demeanor shifts from timid to aggressively domineering. She becomes perpetually furious, often with a throbbing forehead vein. Her interactions involve frequent insults, threats, and tyrannical outbursts directed at others. This personality change endures without reversal.