Mumei is a main character in the anime series 'Koutetsujou no Kabaneri'. She is a mysterious and skilled fighter who belongs to the Kabaneri, beings who are part human and part Kabane. Mumei wields agility and combat prowess, making her a formidable opponent against the Kabane. Throughout the series, she teams up with the protagonist, Ikoma, and the crew of the Koutetsujou to battle the Kabane and find a safe haven. Her journey unveils her past and her struggle for identity, adding depth to her role as both a warrior and a vulnerable young girl.