From the start of her debut, Yumi has been shown to be humble, mild-mannered, and mostly soft-spoken. She has a strong dislike of brutality, and resents her leader and partners Okita and Gohan for their remorselessness in combat. Under pressure, she is often unenthusiastic and pessimistic, fearing the worst that could happen in such situations. She is often reluctant to take leadership in times when it is needed, often allowing her teammates to do such. Despite her feelings towards Tenko, she shows nothing but clear loyalty towards him.