Mutsuki wears a uniform shared with the second member of the Mutsuki-class, Kisaragi. She wears a school uniform-esque garment that is half-opened to expose her navel, with a green skirt and brown pantyhose.

Mutsuki serves somewhat as a sister/mother figurehead for the stubborn, reckless Fubuki and the airheaded, carefree Yuudachi.