Mayumi Joutouguu is the head of the Haniwa Army Corps started by Keiki Haniyasushin. She is an attentive soldier-type who looks out for the safety of those she's been assigned to protect, such as the human spirits. Her surname Joutouguu is likely derived from Joutoujin (杖刀人), a term from the Inariyama sword inscription assumed to be a title or rank related to military affairs. The guu (偶) in her name is the same character in doguu (土偶), which refers to clay figures sometimes incorrectly associated with haniwas despite different period of origin and purpose, and guuzou (偶像), which means "idol". Her first name, Mayumi, is a real-life given name that means "polished bow" in this case. The first kanji "polish" (磨) is related to a typical tool in the ancient ages "polished-stone tools" (磨製石器). On the other hand, "arrow" (弓) is what many haniwa hold in their arms, since they were burden in the tombs of authorities (古墳) in order to guard them. The sound of her personal name "Mayumi" is derived from the voice actress "Mayumi Tanaka" (田中真弓). One of her roles is '"Hanimaru'" (はに丸), the main character of an educational TV program "O~i Hanimaru" (お〜いはに丸).