Muichiro seems to always be forgetting things and his mind is constantly wandering. He doesn't let his emotions control him and his actions are decided based on logic. His disregard for the situation is a deliberate choice, not a lack of observance. It is revealed that Muichiro suffers from amnesia caused by his distressing past. Many of his personality traits line up with the symptoms of PTSD. He has blank turquoise eyes, black long hair the fades to turquoise, oversized demon slayer uniform.