Whereas the Musashi of the established timeline was in fact historically a man, the Miyamoto Musashi that appears in Fate/Grand Order is a young woman—a personage that originated of a timeline long-extinguished by the fall of the Quantum Time-Locks. Since the elimination of her world, she has perpetually shifted from timeline to timeline at random, traversing all varieties of locales and time-periods.

In her original world, 'Miyamoto Musashi' is a nameless swordsman that lives care freely day to day. Shinmen Munisai had abandoned Musashi because she was a girl. Though she was disowned, she built a hut in front of her father's house and lived there just to spite him.

As you see, the person herself has a relaxed, open attitude that never gets worked up. Having no particular interest in victory or prestige, yet sloven with alcohol, a sucker for money and weak against free food. However, all those who confronted and were beaten by her in battle said this in the end:

───a vibrant flower of tengen. Her sword reaches the heights of nothingness.

Cheerful and openhearted, a female swordsman that is lively yet dignified. Constantly full of pride, acting complacently, but that does not mean she is looking down on her opponent. She is merely enjoying life. Her way of expressing emotions is somewhat great. She greatly laughs and gets greatly surprised. While she has a broad-minded personality that laughs off at most things, due being “someone who masters the way of the sword” at her roots, she is very dry and severe in regards to the taking of lives.

That being said, she falls in love easily and likes to be depended on very much. She also likes to be praised very much. Weak to flattery. A banchou disposition that loves a brawl. Although she has a sense of justice, she never preaches to be righteous herself. Fundamentally a carefree wandering vagabond, but she becomes ruthless when coming across scenes such as:

« A one-sided massacre.”
“Trampling on people’s dignity, convictions for fun”
“Stealing my food when I’m hungry. »
(Musashi)

She is happy about the other world's Musashi became a really famous figure.

« Eh? The Musashi in this world is a man?”
“And also extremely famous? What a surprise! »
(Musashi)