Musashi functions as the automaton captain commanding the flying city-ship Musashi and its eight subordinate vessels. She has dark blue hair styled in a ponytail with evenly parted forelocks and turquoise eyes. Her outfit resembles a blue and white maid uniform featuring puffed shoulders, long sleeves, and a voluminous skirt, matching the design consistency of her subordinates.

Her personality reflects standard automaton traits: an emotionless voice and face, flawless logic, and a sharp, critical tone. She delivers notably blunt and pragmatic assessments. For example, she ranks bridge personnel based on usefulness, placing Suzu and Asama highest for sensory support and divine transmissions, while ranking the Chancellor (Tori Aoi) lowest due to disruptive behaviors like nudity, sleeping, and playing pornographic games on bridge monitors.

Her primary ability is gravitational manipulation, a racial trait common among automatons. This power enables her to redirect gravity in specific areas, deploy protective Sign Frame shields around the ship, and activate gravitational acceleration modes for rapid long-distance travel.

She consistently concludes statements with the word "ijou" (以上), meaning "over," underscoring her formal and detached communication style.