Since the death of his family, Muichiro was transferred to an orphanage, he is now 14 years old, since at least he was 11-10 years old he has been here.

Your family is also dead and you have been here almost since you're born. Muichiro is calm and almost empty at times, but agile. Following the violent death of his brother which he had to witness, he has memory loss about his past and even sometimes in the present, he appears neutral and calm.

Muichiro is a young boy of fair skin and short stature with long, straight hair of a raven-black color that fades to a cyan color as it approaches his waist. He wears his hair loose with two clumps protruding slightly from each side of his head, a set of marginally shorter hair left down to frame his face, and unruly bangs over his forehead. He also possesses large, empty-looking cyan eyes.

He is identical in appearance to his older twin brother Yuichiro who is now dead.

Muichiro is an airheaded individual who seems to constantly wander off in his thoughts and never focus on one thing. Impassive and sometimes obtuse, he tends to think only for himself and operates solely on logic, never letting emotion guide him. All of this happens before he becomes a Hashira.