Muichiro is a Demon Slayer of the Demon Slayer Corps and the current Mist Hashira. He is also a descendant of the Upper Rank One, Kokushibo. An air-headed and sleepy individual, with a very forgetful personality who constantly wanders off in thought and is unable to focus at anything, though he gets serious when it is required and is devoted to his position as the Mist Hashira. He is the youngest hashira at age 14. His twin brother Yuichiro died at 10, but he had forgotten about it. Has amnesia.