Kirumi's nature is refined and mature, having a keen mindset and talent in a large handful of subjects. Described as one who 'does their job perfectly in a professional way', every task she carries out is done just as she is asked to do so. She's extremely polite and states that her only desire is to fulfill other people's wishes and requests, obviously putting others before her own self. She voluntarily makes breakfast and cleans the students' dorm rooms without being asked for, since her duty is instinct to her. To sum it up, she's the 'mom' character of the group.

Kirumi has an elegant and composed voice that's just underneath the mid tones.