Muichiro is an air-headed individual who seems to constantly wander off in thought and is unable to focus on anything. Impassive and, at times, obtuse, he tends to think only for himself and operates on logic alone, never letting emotions guide him, making him seem seemingly apathetic and indifferent. However, Tanjiro Kamado sensed that Muichiro wasn't being apathetic on purpose as he didn't emanate any animosity. Despite his mostly uncaring and unserious demeanor, he has been shown to become serious when it is required and is devoted to his position as the Demon Slayer Corps' Mist Hashira. Alternatively he seems to display a cold and arrogant side; as shown by him violently shaking down Kotetsu and calling him stupid, saying his time as a Hashira was important, more so than his own, and that all that the swordsmiths could do was make weapons. Despite this, Muichiro doesn't seem to be indifferent towards Kagaya Ubuyashiki, most likely due to his immense respect for his master.