Muichiro Tokito

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.
Muichiro's original cheery and optimistic disposition.
However, before the death of his twin brother when the siblings were eleven, Muichiro's personality was that of a much more compassionate and optimistic individual, the polar opposite of his current disposition. Having originally taken after his father, he was shown to display a higher level of kindness and understanding, believing he should aim to do good for others if he wanted good to be done for him. When told by Amane Ubuyashiki that they were descendants to Demon Slayers of old, Muichiro became excited at the prospect of being able to protect people.
After his brother was attacked by a demon and witnessing his final moments and death, Muichiro subsequently lost his memories and has held an omnipresent rage deeply suppressed inside of him that inevitably drove his future, intense training. After this memory loss, he started exhibiting the indifferent attitude of his twin brother he is now known for as a Hashira.

Muichiro is a young boy of fair skin and short stature with a lean muscular build along 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.
Following his meeting with Tanjiro Kamado and the return of his childhood memories, Muichiro's once empty looking eyes seem to now have a hopeful glimmer that is accompanied with a more upbeat and cheery expression, reminiscent of his former demeanor before the death of Yuichiro.
Muichiro wears a black standard Demon Slayer uniform, tinted bluish black in the anime, consisting of a button-up jacket with a stand collar. However, he wears longer, looser sleeves that are more reminiscent of those of a kimono than of the standard uniform shirt-like cuff sleeves. Along with this, in the place of the standard tattsuke hakama wrapped by a pair of white kyahan around his calves, he wears his hakama in the umanori style, that along his style of sleeves, gives a loose and oversized appearance to his whole garment. He also has dark blue tabi socks and a pair of white zōri with dark blue straps.

• Muichiro's surname contains the Kun'yomi reading of the kanji for "time" (時とき toki) and the Kan-on'yomi for "transparent, permeate" (透とう tō). His first name contains the Go-on'yomi for "nothingness" (無む mu), "one" (一いち ichi and "son" (郎ろう rō)
• The first kanji of Muichiro's first name, "nothingness" (無む mu) is noted to also be used to write the word "infinity" (無む限げん mugen.
• Additionally, its meaning of "nothingness" stands in stark opposition to the first kanji of his twin brother Yuichiro's name, as that kanji means "existence".
• Not only do Muichiro and Kokushibo share the commonality of having twin siblings, but Muichiro also shares the letter "M" with Kokushibo's human name, Michikatsu. Coincidentally, Muichiro's older twin brother Yuichiro shares the initial "Y" with Michikatsu's younger twin brother, Yoriichi Tsugikuni. In addition, both Muichiro and Yuichiro have the character for "one" (一いち ichi) in their names when Kokushibo holds the position of Upper Rank One.